linux-toradex.git/drivers/mmc/core, branch v4.2.7

mmc: core: Fix init_card in 52Mhz

2015-11-09T22:37:30+00:00

commit 08b137d90eec51b0e90c42e123ca8ceb118d233f upstream.

Suppose that we got a data crc error, and it triggers the mmc_reset.
mmc_reset will call mmc_send_status to see if HW reset was supported.
before issue CMD13, it will do retune, and if EMMC was in HS400 mode,
it will reduce frequency to 52Mhz firstly, then results in card init
was doing at 52Mhz.
The mmc_send_status was originally only done for mmc_test, should drop
it. And, rename the "eMMC hardware reset" to "Reset test", as we would
also be able to use the test for SD-cards.

Signed-off-by: Chaotian Jing 
Suggested-by: Adrian Hunter 
Fixes: bd11e8bd03ca ("mmc: core: Flag re-tuning is needed on CRC errors")
Signed-off-by: Ulf Hansson 
Signed-off-by: Greg Kroah-Hartman

mmc: core: fix dead loop of mmc_retune

2015-10-22T21:49:32+00:00

commit 031277d4d33d33f0174fbb569ca8f68238175617 upstream.

When get a CRC error, start the mmc_retune, it will issue CMD19/CMD21
to do tune, assume there were 10 clock phase need to try, phase 0 to
phase 6 is ok, phase 7 to phase 9 is NG, we try it from 0 to 9, so
the last CMD19/CMD21 will get CRC error, host->need_retune was set and
cause mmc_retune was called, then dead loop of mmc_retune

Signed-off-by: Chaotian Jing 
Acked-by: Adrian Hunter 
Fixes: bd11e8bd03ca ("mmc: core: Flag re-tuning is needed on CRC errors")
Signed-off-by: Ulf Hansson 
Signed-off-by: Greg Kroah-Hartman

mmc: core: Don't return an error for CD/WP GPIOs when GPIOLIB is unset

2015-10-22T21:49:32+00:00

commit 43934ece2ea72c1dd279c0b0478c1a036d5d77ee upstream.

When CONFIG_GPIOLIB is unset, its stubs will return -ENOSYS. That means
when the mmc core parses DT for CD/WP GPIOs via mmc_of_parse(), -ENOSYS
becomes propagated to the caller. Typically this means that the mmc host
driver fails to probe.

As the CD/WP GPIOs are already treated as optional, let's extend that to
cover the case when CONFIG_GPIOLIB is unset.

Reported-by: Michal Simek 
Fixes: 16b23787fc70 ("mmc: sdhci-of-arasan: Call OF parsing for MMC")
Signed-off-by: Ulf Hansson 
Tested-by: Michal Simek 
Acked-by: Venu Byravarasu 
Signed-off-by: Greg Kroah-Hartman

mmc: core: fix race condition in mmc_wait_data_done

2015-09-29T17:33:33+00:00

commit 71f8a4b81d040b3d094424197ca2f1bf811b1245 upstream.

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: Greg Kroah-Hartman

mmc: core: Attach PM domain prior probing of SDIO func driver

2015-06-04T08:03:51+00:00

Other subsystem buses attach PM domains during probe, but prior calling
the driver's ->probe() method. During the removal phase, detaching the PM
domain will be done after invoking the driver's ->remove() callback.

Convert the SDIO bus to follow this behavior and add error handling.

Signed-off-by: Ulf Hansson

mmc: core: Remove redundant ->power_restore() callback for SD

2015-06-04T08:03:51+00:00

Since the ->reset() callback is implemented for SD, the ->power_restore()
callback has become redundant, let's remove it.

Signed-off-by: Ulf Hansson

mmc: core: Remove redundant ->power_restore() callback for MMC

2015-06-04T08:03:51+00:00

Since the ->reset() callback is implemented for MMC, the ->power_restore()
callback has become redundant, let's remove it.

Signed-off-by: Ulf Hansson

mmc: mmc: Add driver strength selection

2015-06-01T07:07:14+00:00

Add the ability to set eMMC driver strength
for HS200 and HS400.

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

mmc: mmc: Read card's valid driver strength mask

2015-06-01T07:07:13+00:00

In preparation for supporing drive strength selection
for eMMC, read the card's valid driver strengths.

Note that though the SD spec uses the term "drive strength",
the JEDEC eMMC spec uses the term "driver strength".

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

mmc: core: Record card drive strength

2015-06-01T07:07:13+00:00

In preparation for adding drive strength support
for eMMC, add drive_strength to struct mmc_card
to record the card drive strength for UHS-I modes
and HS200 / HS400. For eMMC this will be needed
when switching between HS200 and HS400.

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