linux-toradex.git/drivers/mmc/core, branch v3.18.23

mmc: core: fix race condition in mmc_wait_data_done

2015-10-07T14:19:43+00:00

[ Upstream commit 71f8a4b81d040b3d094424197ca2f1bf811b1245 ]

The following panic is captured in ker3.14, but the issue still exists
in latest kernel.
---------------------------------------------------------------------
[   20.738217] c0 3136 (Compiler) Unable to handle kernel NULL pointer dereference
at virtual address 00000578
......
[   20.738499] c0 3136 (Compiler) PC is at _raw_spin_lock_irqsave+0x24/0x60
[   20.738527] c0 3136 (Compiler) LR is at _raw_spin_lock_irqsave+0x20/0x60
[   20.740134] c0 3136 (Compiler) Call trace:
[   20.740165] c0 3136 (Compiler) [] _raw_spin_lock_irqsave+0x24/0x60
[   20.740200] c0 3136 (Compiler) [] __wake_up+0x1c/0x54
[   20.740230] c0 3136 (Compiler) [] mmc_wait_data_done+0x28/0x34
[   20.740262] c0 3136 (Compiler) [] mmc_request_done+0xa4/0x220
[   20.740314] c0 3136 (Compiler) [] sdhci_tasklet_finish+0xac/0x264
[   20.740352] c0 3136 (Compiler) [] tasklet_action+0xa0/0x158
[   20.740382] c0 3136 (Compiler) [] __do_softirq+0x10c/0x2e4
[   20.740411] c0 3136 (Compiler) [] irq_exit+0x8c/0xc0
[   20.740439] c0 3136 (Compiler) [] handle_IRQ+0x48/0xac
[   20.740469] c0 3136 (Compiler) [] gic_handle_irq+0x38/0x7c
----------------------------------------------------------------------
Because in SMP, "mrq" has race condition between below two paths:
path1: CPU0: 
  static void mmc_wait_data_done(struct mmc_request *mrq)
  {
     mrq->host->context_info.is_done_rcv = true;
     //
     // If CPU0 has just finished "is_done_rcv = true" in path1, and at
     // this moment, IRQ or ICache line missing happens in CPU0.
     // What happens in CPU1 (path2)?
     //
     // If the mmcqd thread in CPU1(path2) hasn't entered to sleep mode:
     // path2 would have chance to break from wait_event_interruptible
     // in mmc_wait_for_data_req_done and continue to run for next
     // mmc_request (mmc_blk_rw_rq_prep).
     //
     // Within mmc_blk_rq_prep, mrq is cleared to 0.
     // If below line still gets host from "mrq" as the result of
     // compiler, the panic happens as we traced.
     wake_up_interruptible(&mrq->host->context_info.wait);
  }

path2: CPU1: 
  static int mmc_wait_for_data_req_done(...
  {
     ...
     while (1) {
           wait_event_interruptible(context_info->wait,
                   (context_info->is_done_rcv ||
                    context_info->is_new_req));
     	   static void mmc_blk_rw_rq_prep(...
           {
           ...
           memset(brq, 0, sizeof(struct mmc_blk_request));

This issue happens very coincidentally; however adding mdelay(1) in
mmc_wait_data_done as below could duplicate it easily.

   static void mmc_wait_data_done(struct mmc_request *mrq)
   {
     mrq->host->context_info.is_done_rcv = true;
+    mdelay(1);
     wake_up_interruptible(&mrq->host->context_info.wait);
    }

At runtime, IRQ or ICache line missing may just happen at the same place
of the mdelay(1).

This patch gets the mmc_context_info at the beginning of function, it can
avoid this race condition.

Signed-off-by: Jialing Fu 
Tested-by: Shawn Lin 
Fixes: 2220eedfd7ae ("mmc: fix async request mechanism ....")
Signed-off-by: Shawn Lin 
Signed-off-by: Ulf Hansson 
Signed-off-by: Sasha Levin

mmc: core: add missing pm event in mmc_pm_notify to fix hib restore

2015-06-09T17:43:38+00:00

[ Upstream commit 184af16b09360d6273fd6160e6ff7f8e2482ef23 ]

The PM_RESTORE_PREPARE is not handled now in mmc_pm_notify(),
as result mmc_rescan() could be scheduled and executed at
late hibernation restore stages when MMC device is suspended
already - which, in turn, will lead to system crash on TI dra7-evm board:

WARNING: CPU: 0 PID: 3188 at drivers/bus/omap_l3_noc.c:148 l3_interrupt_handler+0x258/0x374()
44000000.ocp:L3 Custom Error: MASTER MPU TARGET L4_PER1_P3 (Idle): Data Access in User mode during Functional access

Hence, add missed PM_RESTORE_PREPARE PM event in mmc_pm_notify().

Fixes: 4c2ef25fe0b8 (mmc: fix all hangs related to mmc/sd card...)
Signed-off-by: Grygorii Strashko 
Signed-off-by: Ulf Hansson 
Signed-off-by: Sasha Levin

mmc: core: fix card detection regression

2014-11-05T08:28:48+00:00

Since commit 89168b489915 ("mmc: core: restore detect line inversion
semantics"), the SD card on i.MX28 (and possibly other) devices isn't
detected and booting stops at:

[    4.120617] Waiting for root device /dev/mmcblk0p3...

This is caused by the MMC_CAP2_CD_ACTIVE_HIGH flag being set incorrectly
when the host controller doesn't use a GPIO for card detection (but
instead uses a dedicated pin). In this case mmc_gpiod_request_cd() will
return before assigning to the gpio_invert variable, leaving the
variable uninitialized. The variable then gets used to set the flag.
This patch fixes the issue by making sure gpio_invert is set to false
when a GPIO isn't used. After this patch, i.MX28 boots fine.

The MMC_CAP2_RO_ACTIVE_HIGH (write protect) flag is also set incorrectly
for the exact same reason (it uses the same uninitialized variable), so
this patch fixes that too.

Fixes: 89168b489915 ("mmc: core: restore detect line inversion semantics")
Reported-by: Stefan Wahren 
Signed-off-by: Kristina Martšenko 
Tested-by: Fabio Estevam 
Signed-off-by: Ulf Hansson

Merge tag 'mmc-v3.18-1' of git://git.linaro.org/people/ulf.hansson/mmc

2014-10-11T10:34:22+00:00

Pull MMC updates from Ulf Hansson:
 "MMC core:
   - Fix SDIO IRQ bug
   - MMC regulator improvements
   - Fix slot-gpio card detect bug
   - Add support for Driver Stage Register
   - Convert the common MMC OF parser to use GPIO descriptors
   - Convert MMC_CAP2_NO_MULTI_READ into a callback, ->multi_io_quirk()
   - Some additional minor fixes

  MMC host:
   - mmci: Support Qualcomm specific DML layer for DMA
   - dw_mmc: Use common MMC regulators
   - dw_mmc: Add support for Rock-chips RK3288
   - tmio: Enable runtime PM support
   - tmio: Add support for R-Car Gen2 SoCs
   - tmio: Several fixes and improvements
   - omap_hsmmc: Removed Balaji from MAINTAINERS
   - jz4740: add DMA and pre/post support
   - sdhci: Add support for Intel Braswell
   - sdhci: Several fixes and improvements"

* tag 'mmc-v3.18-1' of git://git.linaro.org/people/ulf.hansson/mmc: (119 commits)
  ARM: dts: fix MMC2 regulators for Exynos5420 Arndale Octa board
  mmc: sdhci-acpi: Fix Braswell eMMC timeout clock frequency
  mmc: sdhci-acpi: Pass HID and UID to probe_slot
  mmc: sdhci-acpi: Get UID directly from acpi_device
  mmc, sdhci, bcm-kona, LLVMLinux: Remove use of __initconst
  mmc: sdhci-pci: Fix Braswell eMMC timeout clock frequency
  mmc: sdhci: Let a driver override timeout clock frequency
  mmc: sdhci-pci: Add Bay Trail and Braswell SD card detect
  mmc: sdhci-pci: Set SDHCI_QUIRK2_STOP_WITH_TC for Intel BYT host controllers
  mmc: sdhci-acpi: Add a HID and UID for a SD Card host controller
  mmc: sdhci-acpi: Set SDHCI_QUIRK2_STOP_WITH_TC for Intel host controllers
  mmc: sdhci: Add quirk for always getting TC with stop cmd
  mmc: core: restore detect line inversion semantics
  mmc: Fix incorrect warning when setting 0 Hz via debugfs
  mmc: Fix use of wrong device in mmc_gpiod_free_cd()
  mmc: atmel-mci: fix mismatched section on atmci_cleanup_slot
  mmc: rtsx_pci: Set power related cap2 macros
  mmc: core: Add new power_mode MMC_POWER_UNDEFINED
  mmc: sdhci: execute tuning when device is not busy
  mmc: atmel-mci: Release mmc resources on failure in probe
  ..

mmc: core: restore detect line inversion semantics

2014-10-02T09:51:26+00:00

commit 98e90de99a0c43bd434da814c882c4332441871e
"mmc: host: switch OF parser to use gpio descriptors"
switched the semantic behaviour of card detect and read
only flags such that the inversion capability flag would
only be set if inversion was explicitly specified in the
device tree, in the hopes that no-one was using double
inversion.

It turns out that the XOR:ing between the explicit
inversion was indeed in use, so we need to restore the
old semantics where both ways of inversion are checked
and the end result XOR:ed.

Reported-by: Javier Martinez Canillas 
Tested-by: Javier Martinez Canillas 
Signed-off-by: Linus Walleij 
Signed-off-by: Ulf Hansson

PM / Domains: Move dev_pm_domain_attach|detach() to pm_domain.h

2014-09-29T23:16:44+00:00

The commit 46420dd73b80 (PM / Domains: Add APIs to attach/detach a PM
domain for a device) started using errno values in pm.h header file.
It also failed to include the header for these, thus it caused
compiler errors.

Instead of including the errno header to pm.h, let's move the functions
to pm_domain.h, since it's a better match.

Fixes: 46420dd73b80 (PM / Domains: Add APIs to attach/detach a PM domain for a device)
Signed-off-by: Ulf Hansson 
Acked-by: Geert Uytterhoeven 
Acked-by: Wolfram Sang 
Acked-by: Mark Brown 
Signed-off-by: Rafael J. Wysocki

mmc: Fix incorrect warning when setting 0 Hz via debugfs

2014-09-29T09:41:21+00:00

It is possible to turn off the card clock by setting
the frequency to zero via debugfs e.g.

	echo 0 > /sys/kernel/debug/mmc0/clock

However that produces an incorrect warning that is
designed to warn if the frequency is below the minimum
operating frequency.  So correct the warning.

Signed-off-by: Adrian Hunter 
Signed-off-by: Ulf Hansson

mmc: Fix use of wrong device in mmc_gpiod_free_cd()

2014-09-29T09:27:51+00:00

mmc_gpiod_free_cd() is paired with mmc_gpiod_request_cd()
and both must reference the same device which is the
actual host controller device not the mmc_host class
device.

Signed-off-by: Adrian Hunter 
Signed-off-by: Ulf Hansson

mmc: core: Add new power_mode MMC_POWER_UNDEFINED

2014-09-24T09:20:04+00:00

Add MMC_POWER_UNDEFINED for power_mode in struct mmc_ios and use it as
the initial value of host->ios.power_mode.

For hosts with MMC_CAP2_NO_PRESCAN_POWERUP, this makes the later
mmc_power_off() do real power-off things instead of NOP, and further
prevents state messed up in cards that was already initialized (eg. by
BIOS of UEFI driver).

Signed-off-by: Roger Tseng 
Signed-off-by: Ulf Hansson

mmc: Convert pr_warning to pr_warn

2014-09-24T08:13:09+00:00

Use the much more common pr_warn instead of pr_warning.

Other miscellanea:

o Coalesce formats
o Realign arguments
o Remove extra spaces when coalescing formats

Signed-off-by: Joe Perches 
Signed-off-by: Ulf Hansson