linux-toradex.git/drivers/rtc, branch v4.9.66 Linux kernel for Apalis and Colibri modules rtc: rx8010: change lock mechanism 2017-11-21T08:23:25+00:00 Fabien Lahoudere fabien.lahoudere@collabora.co.uk 2016-12-20T08:42:44+00:00 d9a5790b214527e2a73b602f1ded4f509e3fe04b [ Upstream commit 666b5d1e9f8762300a410f9548b6e370d71dd382 ] Remove spinlock and use the "rtc->ops_lock" from RTC subsystem instead. spin_lock_irqsave() is not needed here because we do not have hard IRQs. This patch fixes the following issue: root@GE004097290448 b850v3:~# hwclock --systohc root@GE004097290448 b850v3:~# hwclock --systohc root@GE004097290448 b850v3:~# hwclock --systohc root@GE004097290448 b850v3:~# hwclock --systohc root@GE004097290448 b850v3:~# hwclock --systohc [ 82.108175] BUG: spinlock wrong CPU on CPU#0, hwclock/855 [ 82.113660] lock: 0xedb4899c, .magic: dead4ead, .owner: hwclock/855, .owner_cpu: 1 [ 82.121329] CPU: 0 PID: 855 Comm: hwclock Not tainted 4.8.0-00042-g09d5410-dirty #20 [ 82.129078] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) [ 82.135609] Backtrace: [ 82.138090] [<8010d378>] (dump_backtrace) from [<8010d5c0>] (show_stack+0x20/0x24) [ 82.145664] r7:ec936000 r6:600a0013 r5:00000000 r4:81031680 [ 82.151402] [<8010d5a0>] (show_stack) from [<80401518>] (dump_stack+0xb4/0xe8) [ 82.158636] [<80401464>] (dump_stack) from [<8017b8b0>] (spin_dump+0x84/0xcc) [ 82.165775] r10:00000000 r9:ec936000 r8:81056090 r7:600a0013 r6:edb4899c r5:edb4899c [ 82.173691] r4:e5033e00 r3:00000000 [ 82.177308] [<8017b82c>] (spin_dump) from [<8017bcb0>] (do_raw_spin_unlock+0x108/0x130) [ 82.185314] r5:edb4899c r4:edb4899c [ 82.188938] [<8017bba8>] (do_raw_spin_unlock) from [<8094b93c>] (_raw_spin_unlock_irqrestore+0x34/0x54) [ 82.198333] r5:edb4899c r4:600a0013 [ 82.201953] [<8094b908>] (_raw_spin_unlock_irqrestore) from [<8065b090>] (rx8010_set_time+0x14c/0x188) [ 82.211261] r5:00000020 r4:edb48990 [ 82.214882] [<8065af44>] (rx8010_set_time) from [<80653fe4>] (rtc_set_time+0x70/0x104) [ 82.222801] r7:00000051 r6:edb39da0 r5:edb39c00 r4:ec937e8c [ 82.228535] [<80653f74>] (rtc_set_time) from [<80655774>] (rtc_dev_ioctl+0x3c4/0x674) [ 82.236368] r7:00000051 r6:7ecf1b74 r5:00000000 r4:edb39c00 [ 82.242106] [<806553b0>] (rtc_dev_ioctl) from [<80284034>] (do_vfs_ioctl+0xa4/0xa6c) [ 82.249851] r8:00000003 r7:80284a40 r6:ed1e9c80 r5:edb44e60 r4:7ecf1b74 [ 82.256642] [<80283f90>] (do_vfs_ioctl) from [<80284a40>] (SyS_ioctl+0x44/0x6c) [ 82.263953] r10:00000000 r9:ec936000 r8:7ecf1b74 r7:4024700a r6:ed1e9c80 r5:00000003 [ 82.271869] r4:ed1e9c80 [ 82.274432] [<802849fc>] (SyS_ioctl) from [<80108520>] (ret_fast_syscall+0x0/0x1c) [ 82.282005] r9:ec936000 r8:801086c4 r7:00000036 r6:00000000 r5:00000003 r4:0008e1bc root@GE004097290448 b850v3:~# Message from syslogd@GE004097290448 at Dec 3 11:17:08 ... kernel:[ 82.108175] BUG: spinlock wrong CPU on CPU#0, hwclock/855 Message from syslogd@GE004097290448 at Dec 3 11:17:08 ... kernel:[ 82.113660] lock: 0xedb4899c, .magic: dead4ead, .owner: hwclock/855, .owner_cpu: 1 hwclock --systohc root@GE004097290448 b850v3:~# Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 666b5d1e9f8762300a410f9548b6e370d71dd382 ]

Remove spinlock and use the "rtc->ops_lock" from RTC subsystem instead.
spin_lock_irqsave() is not needed here because we do not have hard IRQs.

This patch fixes the following issue:

root@GE004097290448 b850v3:~# hwclock --systohc
root@GE004097290448 b850v3:~# hwclock --systohc
root@GE004097290448 b850v3:~# hwclock --systohc
root@GE004097290448 b850v3:~# hwclock --systohc
root@GE004097290448 b850v3:~# hwclock --systohc
[   82.108175] BUG: spinlock wrong CPU on CPU#0, hwclock/855
[   82.113660]  lock: 0xedb4899c, .magic: dead4ead, .owner: hwclock/855, .owner_cpu: 1
[   82.121329] CPU: 0 PID: 855 Comm: hwclock Not tainted 4.8.0-00042-g09d5410-dirty #20
[   82.129078] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[   82.135609] Backtrace:
[   82.138090] [<8010d378>] (dump_backtrace) from [<8010d5c0>] (show_stack+0x20/0x24)
[   82.145664]  r7:ec936000 r6:600a0013 r5:00000000 r4:81031680
[   82.151402] [<8010d5a0>] (show_stack) from [<80401518>] (dump_stack+0xb4/0xe8)
[   82.158636] [<80401464>] (dump_stack) from [<8017b8b0>] (spin_dump+0x84/0xcc)
[   82.165775]  r10:00000000 r9:ec936000 r8:81056090 r7:600a0013 r6:edb4899c r5:edb4899c
[   82.173691]  r4:e5033e00 r3:00000000
[   82.177308] [<8017b82c>] (spin_dump) from [<8017bcb0>] (do_raw_spin_unlock+0x108/0x130)
[   82.185314]  r5:edb4899c r4:edb4899c
[   82.188938] [<8017bba8>] (do_raw_spin_unlock) from [<8094b93c>] (_raw_spin_unlock_irqrestore+0x34/0x54)
[   82.198333]  r5:edb4899c r4:600a0013
[   82.201953] [<8094b908>] (_raw_spin_unlock_irqrestore) from [<8065b090>] (rx8010_set_time+0x14c/0x188)
[   82.211261]  r5:00000020 r4:edb48990
[   82.214882] [<8065af44>] (rx8010_set_time) from [<80653fe4>] (rtc_set_time+0x70/0x104)
[   82.222801]  r7:00000051 r6:edb39da0 r5:edb39c00 r4:ec937e8c
[   82.228535] [<80653f74>] (rtc_set_time) from [<80655774>] (rtc_dev_ioctl+0x3c4/0x674)
[   82.236368]  r7:00000051 r6:7ecf1b74 r5:00000000 r4:edb39c00
[   82.242106] [<806553b0>] (rtc_dev_ioctl) from [<80284034>] (do_vfs_ioctl+0xa4/0xa6c)
[   82.249851]  r8:00000003 r7:80284a40 r6:ed1e9c80 r5:edb44e60 r4:7ecf1b74
[   82.256642] [<80283f90>] (do_vfs_ioctl) from [<80284a40>] (SyS_ioctl+0x44/0x6c)
[   82.263953]  r10:00000000 r9:ec936000 r8:7ecf1b74 r7:4024700a r6:ed1e9c80 r5:00000003
[   82.271869]  r4:ed1e9c80
[   82.274432] [<802849fc>] (SyS_ioctl) from [<80108520>] (ret_fast_syscall+0x0/0x1c)
[   82.282005]  r9:ec936000 r8:801086c4 r7:00000036 r6:00000000 r5:00000003 r4:0008e1bc
root@GE004097290448 b850v3:~#
Message from syslogd@GE004097290448 at Dec  3 11:17:08 ...
 kernel:[   82.108175] BUG: spinlock wrong CPU on CPU#0, hwclock/855

Message from syslogd@GE004097290448 at Dec  3 11:17:08 ...
 kernel:[   82.113660]  lock: 0xedb4899c, .magic: dead4ead, .owner: hwclock/855, .owner_cpu: 1
hwclock --systohc
root@GE004097290448 b850v3:~#

Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rtc: tegra: Implement clock handling 2017-04-21T07:31:24+00:00 Thierry Reding treding@nvidia.com 2017-01-12T16:07:43+00:00 ef793e6e113473f7cb08edf1ca4a8737c57ce51c commit 5fa4086987506b2ab8c92f8f99f2295db9918856 upstream. Accessing the registers of the RTC block on Tegra requires the module clock to be enabled. This only works because the RTC module clock will be enabled by default during early boot. However, because the clock is unused, the CCF will disable it at late_init time. This causes the RTC to become unusable afterwards. This can easily be reproduced by trying to use the RTC: $ hwclock --rtc /dev/rtc1 This will hang the system. I ran into this by following up on a report by Martin Michlmayr that reboot wasn't working on Tegra210 systems. It turns out that the rtc-tegra driver's ->shutdown() implementation will hang the CPU, because of the disabled clock, before the system can be rebooted. What confused me for a while is that the same driver is used on prior Tegra generations where the hang can not be observed. However, as Peter De Schrijver pointed out, this is because on 32-bit Tegra chips the RTC clock is enabled by the tegra20_timer.c clocksource driver, which uses the RTC to provide a persistent clock. This code is never enabled on 64-bit Tegra because the persistent clock infrastructure does not exist on 64-bit ARM. The proper fix for this is to add proper clock handling to the RTC driver in order to ensure that the clock is enabled when the driver requires it. All device trees contain the clock already, therefore no additional changes are required. Reported-by: Martin Michlmayr <tbm@cyrius.com> Acked-By Peter De Schrijver <pdeschrijver@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> [bwh: Backported to 4.9: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5fa4086987506b2ab8c92f8f99f2295db9918856 upstream.

Accessing the registers of the RTC block on Tegra requires the module
clock to be enabled. This only works because the RTC module clock will
be enabled by default during early boot. However, because the clock is
unused, the CCF will disable it at late_init time. This causes the RTC
to become unusable afterwards. This can easily be reproduced by trying
to use the RTC:

	$ hwclock --rtc /dev/rtc1

This will hang the system. I ran into this by following up on a report
by Martin Michlmayr that reboot wasn't working on Tegra210 systems. It
turns out that the rtc-tegra driver's ->shutdown() implementation will
hang the CPU, because of the disabled clock, before the system can be
rebooted.

What confused me for a while is that the same driver is used on prior
Tegra generations where the hang can not be observed. However, as Peter
De Schrijver pointed out, this is because on 32-bit Tegra chips the RTC
clock is enabled by the tegra20_timer.c clocksource driver, which uses
the RTC to provide a persistent clock. This code is never enabled on
64-bit Tegra because the persistent clock infrastructure does not exist
on 64-bit ARM.

The proper fix for this is to add proper clock handling to the RTC
driver in order to ensure that the clock is enabled when the driver
requires it. All device trees contain the clock already, therefore
no additional changes are required.

Reported-by: Martin Michlmayr <tbm@cyrius.com>
Acked-By Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rtc: sun6i: Switch to the external oscillator 2017-03-12T05:41:52+00:00 Maxime Ripard maxime.ripard@free-electrons.com 2017-01-23T10:41:48+00:00 de2aa5b3ee76e97dc3cea33cbd3d1bd443fda7a0 commit fb61bb82cb46a932ef2fc62e1c731c8e7e6640d5 upstream. The RTC is clocked from either an internal, imprecise, oscillator or an external one, which is usually much more accurate. The difference perceived between the time elapsed and the time reported by the RTC is in a 10% scale, which prevents the RTC from being useful at all. Fortunately, the external oscillator is reported to be mandatory in the Allwinner datasheet, so we can just switch to it. Fixes: 9765d2d94309 ("rtc: sun6i: Add sun6i RTC driver") Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fb61bb82cb46a932ef2fc62e1c731c8e7e6640d5 upstream.

The RTC is clocked from either an internal, imprecise, oscillator or an
external one, which is usually much more accurate.

The difference perceived between the time elapsed and the time reported by
the RTC is in a 10% scale, which prevents the RTC from being useful at all.

Fortunately, the external oscillator is reported to be mandatory in the
Allwinner datasheet, so we can just switch to it.

Fixes: 9765d2d94309 ("rtc: sun6i: Add sun6i RTC driver")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rtc: sun6i: Add some locking 2017-03-12T05:41:52+00:00 Maxime Ripard maxime.ripard@free-electrons.com 2017-01-23T10:41:47+00:00 6aae7ffa33072e6d3a208039ac015c1a0fb51e37 commit a9422a19ce270a22fc520f2278fb7e80c58be508 upstream. Some registers have a read-modify-write access pattern that are not atomic. Add some locking to prevent from concurrent accesses. Acked-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a9422a19ce270a22fc520f2278fb7e80c58be508 upstream.

Some registers have a read-modify-write access pattern that are not atomic.

Add some locking to prevent from concurrent accesses.

Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rtc: sun6i: Disable the build as a module 2017-03-12T05:41:52+00:00 Maxime Ripard maxime.ripard@free-electrons.com 2017-01-23T10:41:46+00:00 616f5ef61338a53e997eebbe2c13b21c40df9b86 commit 3753941475ae6501dcd1e41832bd0e6c35247d6a upstream. Since we have to provide the clock very early on, the RTC driver cannot be built as a module. Make sure that won't happen. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3753941475ae6501dcd1e41832bd0e6c35247d6a upstream.

Since we have to provide the clock very early on, the RTC driver cannot be
built as a module. Make sure that won't happen.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rtc: omap: prevent disabling of clock/module during suspend 2016-11-04T22:11:39+00:00 Tero Kristo t-kristo@ti.com 2016-10-27T05:57:26+00:00 efce21fc43e00a76aee7b0a1eda73730ed2d5d3a If RTC is running from an internal clock source, the RTC module can't be disabled; otherwise it stops ticking completely. Current suspend handler implementation disables the clock/module unconditionally, instead fix this by disabling the clock only if we are running on external clock source, which is not affected by suspend. The prevention of disabling the clock must be done via implementing the runtime_pm handlers for the device, and returning an error code from the runtime suspend handler; otherwise OMAP core PM will disable the clocks for the driver. Signed-off-by: Tero Kristo <t-kristo@ti.com> Signed-off-by: Keerthy <j-keerthy@ti.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> 
If RTC is running from an internal clock source, the RTC module can't
be disabled; otherwise it stops ticking completely. Current suspend
handler implementation disables the clock/module unconditionally,
instead fix this by disabling the clock only if we are running on
external clock source, which is not affected by suspend.

The prevention of disabling the clock must be done via implementing
the runtime_pm handlers for the device, and returning an error code
from the runtime suspend handler; otherwise OMAP core PM will disable
the clocks for the driver.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
rtc: omap: Fix selecting external osc 2016-11-04T22:11:37+00:00 Lokesh Vutla lokeshvutla@ti.com 2016-10-27T05:57:25+00:00 3984903a2e3906d3def220e688040ce93368200a RTC can be clocked from an external 32KHz oscillator, or from the Peripheral PLL. The RTC has an internal oscillator buffer to support direct operation with a crystal. ---------------------------------------- | Device --------- | | | | | | | RTCSS | | | --------- | | | OSC |<------| RTC | | | | |------>| OSC |--- | | | | -------- | | | | | ----|clk | | | -------- | | | | | | PRCM |--- | | | | -------- -------- | ---------------------------------------- The RTC functional clock is sourced by default from the clock derived from the Peripheral PLL. In order to select source as external osc clk the following changes needs to be done: - Enable the RTC OSC (RTC_OSC_REG[4]OSC32K_GZ = 0) - Enable the clock mux(RTC_OSC_REG[6]K32CLK_EN = 1) - Select the external clock source (RTC_OSC_REG[3]32KCLK_SEL = 1) Fixes: 399cf0f63f6f2 ("rtc: omap: Add external clock enabling support") Signed-off-by: Keerthy <j-keerthy@ti.com> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com> Signed-off-by: Dave Gerlach <d-gerlach@ti.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> 
RTC can be clocked from an external 32KHz oscillator, or from the
Peripheral PLL. The RTC has an internal oscillator buffer to support
direct operation with a crystal.

            ----------------------------------------
            |       Device          ---------       |
            |                       |       |       |
            |                       | RTCSS |       |
            |       ---------       |       |       |
    OSC     |<------| RTC   |       |       |       |
            |------>| OSC   |---    |       |       |
            |       --------   |    |       |       |
            |                   ----|clk    |       |
            |       --------   |    |       |       |
            |       | PRCM  |---    |       |       |
            |       --------        --------        |
            ----------------------------------------

The RTC functional clock is sourced by default from the clock derived
from the Peripheral PLL. In order to select source as external osc clk
the following changes needs to be done:
- Enable the RTC OSC (RTC_OSC_REG[4]OSC32K_GZ = 0)
- Enable the clock mux(RTC_OSC_REG[6]K32CLK_EN = 1)
- Select the external clock source (RTC_OSC_REG[3]32KCLK_SEL = 1)

Fixes: 399cf0f63f6f2 ("rtc: omap: Add external clock enabling support")
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
rtc: cmos: Don't enable interrupts in the middle of the interrupt handler 2016-10-20T15:40:06+00:00 Ville Syrjälä ville.syrjala@linux.intel.com 2016-10-19T18:02:04+00:00 368e21aebe9535c1643b272aaa9819298a6bc3e5 Using spin_lock_irq()/spin_unlock_irq() from within the interrupt handler is a no-no. Let's save/restore the flags to avoid turning on interrupts prematurely. We hit this in a bunch of our CI systems, but for whatever reason I wasn't able to reproduce on my own machine, so this fix is just based on the backtrace. [ 202.634918] WARNING: CPU: 0 PID: 0 at kernel/locking/lockdep.c:2729 trace_hardirqs_on_caller+0x113/0x1b0 [ 202.634919] DEBUG_LOCKS_WARN_ON(current->hardirq_context) [ 202.634929] Modules linked in: snd_hda_intel i915 x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel lpc_ich snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_codec snd_hwdep i2c_designware_platform i2c_designware_core snd_hda_core mei_me mei snd_pcm r8169 mii sdhci_acpi sdhci mmc_core i2c_hid [last unloaded: i915] [ 202.634930] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G U 4.9.0-rc1-CI-CI_DRM_1734+ #1 [ 202.634931] Hardware name: GIGABYTE M4HM87P-00/M4HM87P-00, BIOS F6 12/10/2014 [ 202.634933] ffff88011ea03d68 ffffffff8142dce5 ffff88011ea03db8 0000000000000000 [ 202.634934] ffff88011ea03da8 ffffffff8107e496 00000aa900000002 ffffffff81e249a0 [ 202.634935] ffffffff81815637 ffffffff82e7c280 0000000000000000 0000000000000004 [ 202.634936] Call Trace: [ 202.634939] <IRQ> [ 202.634939] [<ffffffff8142dce5>] dump_stack+0x67/0x92 [ 202.634941] [<ffffffff8107e496>] __warn+0xc6/0xe0 [ 202.634944] [<ffffffff81815637>] ? _raw_spin_unlock_irq+0x27/0x50 [ 202.634945] [<ffffffff8107e4fa>] warn_slowpath_fmt+0x4a/0x50 [ 202.634946] [<ffffffff810d6d83>] trace_hardirqs_on_caller+0x113/0x1b0 [ 202.634948] [<ffffffff810d6e2d>] trace_hardirqs_on+0xd/0x10 [ 202.634949] [<ffffffff81815637>] _raw_spin_unlock_irq+0x27/0x50 [ 202.634951] [<ffffffff81672042>] rtc_handler+0x32/0xa0 [ 202.634954] [<ffffffff814c08a3>] acpi_ev_fixed_event_detect+0xd4/0xfb [ 202.634956] [<ffffffff814c2ccb>] acpi_ev_sci_xrupt_handler+0xf/0x2d [ 202.634957] [<ffffffff814ab3ee>] acpi_irq+0x11/0x2c [ 202.634960] [<ffffffff810e5288>] __handle_irq_event_percpu+0x58/0x370 [ 202.634961] [<ffffffff810e55be>] handle_irq_event_percpu+0x1e/0x50 [ 202.634962] [<ffffffff810e5624>] handle_irq_event+0x34/0x60 [ 202.634963] [<ffffffff810e8906>] handle_fasteoi_irq+0xa6/0x170 [ 202.634966] [<ffffffff8101eef5>] handle_irq+0x15/0x20 [ 202.634967] [<ffffffff8101e548>] do_IRQ+0x68/0x130 [ 202.634968] [<ffffffff81816789>] common_interrupt+0x89/0x89 [ 202.634970] <EOI> [ 202.634970] [<ffffffff81814c73>] ? mwait_idle+0x93/0x210 [ 202.634971] [<ffffffff81814c6a>] ? mwait_idle+0x8a/0x210 [ 202.634972] [<ffffffff81026b0a>] arch_cpu_idle+0xa/0x10 [ 202.634973] [<ffffffff8181509e>] default_idle_call+0x1e/0x30 [ 202.634974] [<ffffffff810cbf6c>] cpu_startup_entry+0x17c/0x1f0 [ 202.634976] [<ffffffff8180ca87>] rest_init+0x127/0x130 [ 202.634978] [<ffffffff81f77f08>] start_kernel+0x3f6/0x403 [ 202.634980] [<ffffffff81f7728f>] x86_64_start_reservations+0x2a/0x2c [ 202.634981] [<ffffffff81f77404>] x86_64_start_kernel+0x173/0x186 [ 202.634982] ---[ end trace 293c99618fa08d34 ]--- Cc: Gabriele Mazzotta <gabriele.mzt@gmail.com> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> Fixes: 983bf1256edb ("rtc: cmos: Clear ACPI-driven alarms upon resume") Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> 
Using spin_lock_irq()/spin_unlock_irq() from within the interrupt
handler is a no-no. Let's save/restore the flags to avoid turning on
interrupts prematurely.

We hit this in a bunch of our CI systems, but for whatever reason I
wasn't able to reproduce on my own machine, so this fix is just
based on the backtrace.

[  202.634918] WARNING: CPU: 0 PID: 0 at kernel/locking/lockdep.c:2729 trace_hardirqs_on_caller+0x113/0x1b0
[  202.634919] DEBUG_LOCKS_WARN_ON(current->hardirq_context)
[  202.634929] Modules linked in: snd_hda_intel i915 x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel lpc_ich snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_codec snd_hwdep i2c_designware_platform i2c_designware_core snd_hda_core mei_me mei snd_pcm r8169 mii sdhci_acpi sdhci mmc_core i2c_hid [last unloaded: i915]
[  202.634930] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G     U          4.9.0-rc1-CI-CI_DRM_1734+ #1
[  202.634931] Hardware name: GIGABYTE M4HM87P-00/M4HM87P-00, BIOS F6 12/10/2014
[  202.634933]  ffff88011ea03d68 ffffffff8142dce5 ffff88011ea03db8 0000000000000000
[  202.634934]  ffff88011ea03da8 ffffffff8107e496 00000aa900000002 ffffffff81e249a0
[  202.634935]  ffffffff81815637 ffffffff82e7c280 0000000000000000 0000000000000004
[  202.634936] Call Trace:
[  202.634939]  <IRQ>
[  202.634939]  [<ffffffff8142dce5>] dump_stack+0x67/0x92
[  202.634941]  [<ffffffff8107e496>] __warn+0xc6/0xe0
[  202.634944]  [<ffffffff81815637>] ? _raw_spin_unlock_irq+0x27/0x50
[  202.634945]  [<ffffffff8107e4fa>] warn_slowpath_fmt+0x4a/0x50
[  202.634946]  [<ffffffff810d6d83>] trace_hardirqs_on_caller+0x113/0x1b0
[  202.634948]  [<ffffffff810d6e2d>] trace_hardirqs_on+0xd/0x10
[  202.634949]  [<ffffffff81815637>] _raw_spin_unlock_irq+0x27/0x50
[  202.634951]  [<ffffffff81672042>] rtc_handler+0x32/0xa0
[  202.634954]  [<ffffffff814c08a3>] acpi_ev_fixed_event_detect+0xd4/0xfb
[  202.634956]  [<ffffffff814c2ccb>] acpi_ev_sci_xrupt_handler+0xf/0x2d
[  202.634957]  [<ffffffff814ab3ee>] acpi_irq+0x11/0x2c
[  202.634960]  [<ffffffff810e5288>] __handle_irq_event_percpu+0x58/0x370
[  202.634961]  [<ffffffff810e55be>] handle_irq_event_percpu+0x1e/0x50
[  202.634962]  [<ffffffff810e5624>] handle_irq_event+0x34/0x60
[  202.634963]  [<ffffffff810e8906>] handle_fasteoi_irq+0xa6/0x170
[  202.634966]  [<ffffffff8101eef5>] handle_irq+0x15/0x20
[  202.634967]  [<ffffffff8101e548>] do_IRQ+0x68/0x130
[  202.634968]  [<ffffffff81816789>] common_interrupt+0x89/0x89
[  202.634970]  <EOI>
[  202.634970]  [<ffffffff81814c73>] ? mwait_idle+0x93/0x210
[  202.634971]  [<ffffffff81814c6a>] ? mwait_idle+0x8a/0x210
[  202.634972]  [<ffffffff81026b0a>] arch_cpu_idle+0xa/0x10
[  202.634973]  [<ffffffff8181509e>] default_idle_call+0x1e/0x30
[  202.634974]  [<ffffffff810cbf6c>] cpu_startup_entry+0x17c/0x1f0
[  202.634976]  [<ffffffff8180ca87>] rest_init+0x127/0x130
[  202.634978]  [<ffffffff81f77f08>] start_kernel+0x3f6/0x403
[  202.634980]  [<ffffffff81f7728f>] x86_64_start_reservations+0x2a/0x2c
[  202.634981]  [<ffffffff81f77404>] x86_64_start_kernel+0x173/0x186
[  202.634982] ---[ end trace 293c99618fa08d34 ]---

Cc: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Fixes: 983bf1256edb ("rtc: cmos: Clear ACPI-driven alarms upon resume")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
rtc: cmos: remove all __exit_p annotations 2016-10-19T06:45:50+00:00 LABBE Corentin clabbe.montjoie@gmail.com 2016-10-18T14:39:54+00:00 a3a0673b9db6fad2a3f7874c34e4b5cbc5fa01c6 I got the following stack trace under qemu: [ 7.575243] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [ 7.596098] IP: [<ffffffff814f5b08>] cmos_set_alarm+0x38/0x280 [ 7.615699] PGD 3ccbe067 [ 7.615923] PUD 3daf2067 [ 7.635156] PMD 0 [ 7.654358] Oops: 0000 [#1] SMP [ 7.673869] Modules linked in: [ 7.693235] CPU: 0 PID: 1701 Comm: hwclock Tainted: G W 4.9.0-rc1+ #24 [ 7.712455] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 [ 7.753569] task: ffff88003d88dc40 task.stack: ffffc90000224000 [ 7.773743] RIP: 0010:[<ffffffff814f5b08>] [<ffffffff814f5b08>] cmos_set_alarm+0x38/0x280 [ 7.794893] RSP: 0018:ffffc90000227c10 EFLAGS: 00010296 [ 7.815890] RAX: 000000000000001d RBX: ffffc90000227d28 RCX: ffffffff8182be78 [ 7.836057] RDX: 0000000000000001 RSI: 0000000000000202 RDI: 0000000000000202 [ 7.856612] RBP: ffffc90000227c48 R08: 0000000000000000 R09: 0000000000000001 [ 7.877561] R10: 00000000000001c0 R11: 00000000000001c0 R12: 0000000000000000 [ 7.897072] R13: ffff88003d96f400 R14: ffff88003dac6410 R15: ffff88003dac6420 [ 7.917403] FS: 00007f77f42d9700(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000 [ 7.938293] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 7.958364] CR2: 0000000000000010 CR3: 000000003ccbb000 CR4: 00000000000006f0 [ 7.978028] Stack: [ 7.997120] ffff88003dac6000 ffff88003dac6410 0000000058049d01 ffffc90000227d28 [ 8.016993] ffff88003dac6000 ffff88003dac6410 ffff88003dac6420 ffffc90000227c98 [ 8.039505] ffffffff814f225d 0000001800227c98 000000090000002a 0000000900000011 [ 8.059985] Call Trace: [ 8.080110] [<ffffffff814f225d>] __rtc_set_alarm+0x8d/0xa0 [ 8.099421] [<ffffffff814f2389>] rtc_timer_enqueue+0x119/0x190 [ 8.119925] [<ffffffff814f2e6e>] rtc_update_irq_enable+0xbe/0x100 [ 8.140583] [<ffffffff814f3bb0>] rtc_dev_ioctl+0x3c0/0x480 [ 8.161162] [<ffffffff81146b6a>] ? user_path_at_empty+0x3a/0x50 [ 8.182717] [<ffffffff8114aa36>] do_vfs_ioctl+0x96/0x5c0 [ 8.204624] [<ffffffff8113e066>] ? vfs_stat+0x16/0x20 [ 8.225994] [<ffffffff8113e135>] ? SyS_newstat+0x15/0x30 [ 8.247043] [<ffffffff8114afa7>] SyS_ioctl+0x47/0x80 [ 8.267191] [<ffffffff815f5c77>] entry_SYSCALL_64_fastpath+0x1a/0xa9 [ 8.288719] Code: 6a 81 48 89 e5 41 57 41 56 41 55 49 89 fd 41 54 53 48 89 f3 48 c7 c6 20 c4 78 81 48 83 ec 10 e8 8f 00 ef ff 4d 8b a5 a0 00 00 00 <41> 8b 44 24 10 85 c0 0f 8e 2b 02 00 00 4c 89 ef 31 c0 b9 53 01 [ 8.335233] RIP [<ffffffff814f5b08>] cmos_set_alarm+0x38/0x280 [ 8.357096] RSP <ffffc90000227c10> [ 8.379051] CR2: 0000000000000010 [ 8.401736] ---[ end trace 5cbcd83a1f225ed3 ]--- This occur only when CONFIG_DEBUG_TEST_DRIVER_REMOVE is enabled and CONFIG_RTC_DRV_CMOS builtin. When cmos_set_alarm() is called dev is NULL and so trigger the deref via cmos->irq The problem comes from that the device is removed but no remove function are called due to _exit_p(). This patch remove all _exit_p() annotation. Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> 
I got the following stack trace under qemu:
[    7.575243] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
[    7.596098] IP: [<ffffffff814f5b08>] cmos_set_alarm+0x38/0x280
[    7.615699] PGD 3ccbe067
[    7.615923] PUD 3daf2067
[    7.635156] PMD 0
[    7.654358] Oops: 0000 [#1] SMP
[    7.673869] Modules linked in:
[    7.693235] CPU: 0 PID: 1701 Comm: hwclock Tainted: G        W       4.9.0-rc1+ #24
[    7.712455] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
[    7.753569] task: ffff88003d88dc40 task.stack: ffffc90000224000
[    7.773743] RIP: 0010:[<ffffffff814f5b08>]  [<ffffffff814f5b08>] cmos_set_alarm+0x38/0x280
[    7.794893] RSP: 0018:ffffc90000227c10  EFLAGS: 00010296
[    7.815890] RAX: 000000000000001d RBX: ffffc90000227d28 RCX: ffffffff8182be78
[    7.836057] RDX: 0000000000000001 RSI: 0000000000000202 RDI: 0000000000000202
[    7.856612] RBP: ffffc90000227c48 R08: 0000000000000000 R09: 0000000000000001
[    7.877561] R10: 00000000000001c0 R11: 00000000000001c0 R12: 0000000000000000
[    7.897072] R13: ffff88003d96f400 R14: ffff88003dac6410 R15: ffff88003dac6420
[    7.917403] FS:  00007f77f42d9700(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000
[    7.938293] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    7.958364] CR2: 0000000000000010 CR3: 000000003ccbb000 CR4: 00000000000006f0
[    7.978028] Stack:
[    7.997120]  ffff88003dac6000 ffff88003dac6410 0000000058049d01 ffffc90000227d28
[    8.016993]  ffff88003dac6000 ffff88003dac6410 ffff88003dac6420 ffffc90000227c98
[    8.039505]  ffffffff814f225d 0000001800227c98 000000090000002a 0000000900000011
[    8.059985] Call Trace:
[    8.080110]  [<ffffffff814f225d>] __rtc_set_alarm+0x8d/0xa0
[    8.099421]  [<ffffffff814f2389>] rtc_timer_enqueue+0x119/0x190
[    8.119925]  [<ffffffff814f2e6e>] rtc_update_irq_enable+0xbe/0x100
[    8.140583]  [<ffffffff814f3bb0>] rtc_dev_ioctl+0x3c0/0x480
[    8.161162]  [<ffffffff81146b6a>] ? user_path_at_empty+0x3a/0x50
[    8.182717]  [<ffffffff8114aa36>] do_vfs_ioctl+0x96/0x5c0
[    8.204624]  [<ffffffff8113e066>] ? vfs_stat+0x16/0x20
[    8.225994]  [<ffffffff8113e135>] ? SyS_newstat+0x15/0x30
[    8.247043]  [<ffffffff8114afa7>] SyS_ioctl+0x47/0x80
[    8.267191]  [<ffffffff815f5c77>] entry_SYSCALL_64_fastpath+0x1a/0xa9
[    8.288719] Code: 6a 81 48 89 e5 41 57 41 56 41 55 49 89 fd 41 54 53 48 89 f3 48 c7 c6 20 c4 78 81 48 83 ec 10 e8 8f 00 ef ff 4d 8b a5 a0 00 00 00 <41> 8b 44 24 10 85 c0 0f 8e 2b 02 00 00 4c 89 ef 31 c0 b9 53 01
[    8.335233] RIP  [<ffffffff814f5b08>] cmos_set_alarm+0x38/0x280
[    8.357096]  RSP <ffffc90000227c10>
[    8.379051] CR2: 0000000000000010
[    8.401736] ---[ end trace 5cbcd83a1f225ed3 ]---

This occur only when CONFIG_DEBUG_TEST_DRIVER_REMOVE is enabled and
CONFIG_RTC_DRV_CMOS builtin.

When cmos_set_alarm() is called dev is NULL and so trigger the deref via
cmos->irq

The problem comes from that the device is removed but no remove function
are called due to _exit_p().

This patch remove all _exit_p() annotation.

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
rtc: asm9260: fix module autoload 2016-10-19T06:45:48+00:00 Javier Martinez Canillas javier@osg.samsung.com 2016-10-14T13:15:35+00:00 aa156c8aee22a24865bf94d0c4a5f604f687fa7d If the driver is built as a module, autoload won't work because the module alias information is not filled so user-space can't match the registered device with the corresponding module. Export the module alias information using the MODULE_DEVICE_TABLE() macro. Before this patch: $ modinfo drivers/rtc/rtc-asm9260.ko | grep alias $ After this patch: $ modinfo drivers/rtc/rtc-asm9260.ko | grep alias alias: of:N*T*Calphascale,asm9260-rtcC* alias: of:N*T*Calphascale,asm9260-rtc Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> 
If the driver is built as a module, autoload won't work because the module
alias information is not filled so user-space can't match the registered
device with the corresponding module.

Export the module alias information using the MODULE_DEVICE_TABLE() macro.

Before this patch:

$ modinfo drivers/rtc/rtc-asm9260.ko | grep alias
$

After this patch:

$ modinfo drivers/rtc/rtc-asm9260.ko | grep alias
alias:          of:N*T*Calphascale,asm9260-rtcC*
alias:          of:N*T*Calphascale,asm9260-rtc

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>