linux.git/drivers/mmc/core/sd.c, branch v6.0

mmc: core: Terminate infinite loop in SD-UHS voltage switch

2022-09-21T12:36:08+00:00

This loop intends to retry a max of 10 times, with some implicit
termination based on the SD_{R,}OCR_S18A bit. Unfortunately, the
termination condition depends on the value reported by the SD card
(*rocr), which may or may not correctly reflect what we asked it to do.

Needless to say, it's not wise to rely on the card doing what we expect;
we should at least terminate the loop regardless. So, check both the
input and output values, so we ensure we will terminate regardless of
the SD card behavior.

Note that SDIO learned a similar retry loop in commit 0797e5f1453b
("mmc: core: Fixup signal voltage switch"), but that used the 'ocr'
result, and so the current pre-terminating condition looks like:

    rocr & ocr & R4_18V_PRESENT

(i.e., it doesn't have the same bug.)

This addresses a number of crash reports seen on ChromeOS that look
like the following:

    ... // lots of repeated: ...
    <4>[13142.846061] mmc1: Skipping voltage switch
    <4>[13143.406087] mmc1: Skipping voltage switch
    <4>[13143.964724] mmc1: Skipping voltage switch
    <4>[13144.526089] mmc1: Skipping voltage switch
    <4>[13145.086088] mmc1: Skipping voltage switch
    <4>[13145.645941] mmc1: Skipping voltage switch
    <3>[13146.153969] INFO: task halt:30352 blocked for more than 122 seconds.
    ...

Fixes: f2119df6b764 ("mmc: sd: add support for signal voltage switch procedure")
Cc: 
Signed-off-by: Brian Norris 
Reviewed-by: Guenter Roeck 
Link: https://lore.kernel.org/r/20220914014010.2076169-1-briannorris@chromium.org
Signed-off-by: Ulf Hansson

mmc: core: Fix inconsistent sd3_bus_mode at UHS-I SD voltage switch failure

2022-08-22T10:58:28+00:00

If re-initialization results is a different signal voltage, because the
voltage switch failed previously, but not this time (or vice versa), then
sd3_bus_mode will be inconsistent with the card because the SD_SWITCH
command is done only upon first initialization.

Fix by always reading SD_SWITCH information during re-initialization, which
also means it does not need to be re-read later for the 1.8V fixup
workaround.

Note, brief testing showed SD_SWITCH took about 1.8ms to 2ms which added
about 1% to 1.5% to the re-initialization time, so it's not particularly
significant.

Reported-by: Seunghui Lee 
Signed-off-by: Adrian Hunter 
Reviewed-by: Seunghui Lee 
Tested-by: Seunghui Lee 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220815073321.63382-3-adrian.hunter@intel.com
Signed-off-by: Ulf Hansson

mmc: core: Fix UHS-I SD 1.8V workaround branch

2022-08-22T10:58:28+00:00

When introduced, upon success, the 1.8V fixup workaround in
mmc_sd_init_card() would branch to practically the end of the function, to
a label named "done". Unfortunately, perhaps due to the label name, over
time new code has been added that really should have come after "done" not
before it. Let's fix the problem by moving the label to the correct place
and rename it "cont".

Fixes: 045d705dc1fb ("mmc: core: Enable the MMC host software queue for the SD card")
Signed-off-by: Adrian Hunter 
Reviewed-by: Seunghui Lee 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220815073321.63382-2-adrian.hunter@intel.com
Signed-off-by: Ulf Hansson

mmc: core: Use mmc_card_* macro and add a new for the sd_combo type

2022-07-13T10:44:41+00:00

Add mmc_card_sd_combo() macro for sd combo type card and use the mmc_card_*
macro to simplify code instead of comparing card->type.

Signed-off-by: Seunghui Lee 
Link: https://lore.kernel.org/r/20220713033635.28432-2-sh043.lee@samsung.com
Signed-off-by: Ulf Hansson

mmc: core: Replace with already defined values for readability

2022-07-12T10:38:49+00:00

SD_ROCR_S18A is already defined and is used to check the rocr value, so
let's replace with already defined values for readability.

Signed-off-by: ChanWoo Lee 
Reviewed-by: Linus Walleij 
Link: https://lore.kernel.org/r/20220706004840.24812-1-cw9316.lee@samsung.com
Signed-off-by: Ulf Hansson

mmc: core: Add CIDs for cards to the entropy pool

2022-04-26T13:39:37+00:00

To make the entropy pool a bit better we can toss in the
CID for eMMC and SD cards into it, usually the serial
number portion is at least unique.

This does not count as improvement of the entropy but
in practice it makes it a bit more random to mix in these
numbers.

Cc: Theodore Ts'o 
Acked-by: Jason A. Donenfeld 
Signed-off-by: Linus Walleij 
Link: https://lore.kernel.org/r/20220425205442.1347837-1-linus.walleij@linaro.org
Signed-off-by: Ulf Hansson

Merge branch 'fixes' into next

2022-03-07T11:53:29+00:00

mmc: core: Restore (almost) the busy polling for MMC_SEND_OP_COND

2022-03-07T10:47:39+00:00

Commit 76bfc7ccc2fa ("mmc: core: adjust polling interval for CMD1"),
significantly decreased the polling period from ~10-12ms into just a couple
of us. The purpose was to decrease the total time spent in the busy polling
loop, but unfortunate it has lead to problems, that causes eMMC cards to
never gets out busy and thus fails to be initialized.

To fix the problem, but also to try to keep some of the new improved
behaviour, let's start by using a polling period of 1-2ms, which then
increases for each loop, according to common polling loop in
__mmc_poll_for_busy().

Reported-by: Jean Rene Dawin 
Reported-by: H. Nikolaus Schaller 
Cc: Huijin Park 
Fixes: 76bfc7ccc2fa ("mmc: core: adjust polling interval for CMD1")
Signed-off-by: Ulf Hansson 
Tested-by: Jean Rene Dawin 
Tested-by: H. Nikolaus Schaller 
Link: https://lore.kernel.org/r/20220304105656.149281-1-ulf.hansson@linaro.org

mmc: core: use sysfs_emit() instead of sprintf()

2022-02-28T12:06:23+00:00

sprintf() (still used in the MMC core for the sysfs output) is vulnerable
to the buffer overflow.  Use the new-fangled sysfs_emit() instead.

Found by Linux Verification Center (linuxtesting.org) with the SVACE static
analysis tool.

Signed-off-by: Sergey Shtylyov 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/717729b2-d65b-c72e-9fac-471d28d00b5a@omp.ru
Signed-off-by: Ulf Hansson

mmc: core: Wait for command setting 'Power Off Notification' bit to complete

2022-01-24T14:37:13+00:00

SD card is allowed to signal busy on DAT0 up to 1s after the
CMD49. According to SD spec (version 6.0 section 5.8.1.3) first host
waits until busy of CMD49 is released and only then polls Power
Management Status register up to 1s until the card indicates ready to
power off.

Without waiting for busy before polling status register sometimes card
becomes unresponsive and system fails to suspend:

  [  205.907459] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
  [  206.421274] sunxi-mmc 1c0f000.mmc: data error, sending stop command
  [  206.421321] sunxi-mmc 1c0f000.mmc: send stop command failed
  [  206.421347] mmc0: error -110 reading status reg of PM func
  [  206.421366] PM: dpm_run_callback(): mmc_bus_suspend+0x0/0x74 returns -110
  [  206.421402] mmcblk mmc0:aaaa: PM: failed to suspend async: error -110
  [  206.437064] PM: Some devices failed to suspend, or early wake event detected

Tested with Sandisk Extreme PRO A2 64GB on Allwinner A64 system.

Signed-off-by: Andrey Skvortsov 
Fixes: 2c5d42769038 ("mmc: core: Add support for Power Off Notification for SD cards")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220115121447.641524-1-andrej.skvortzov@gmail.com
Signed-off-by: Ulf Hansson