linux/drivers/mmc/core
Stefan Wahren f7bf11a3a2 mmc: core: Use maximum timeout values in case TACC field is zero
When plugging a specific micro SD card at MMC socket of a custom i.MX28 board,
we get the following kernel warning:

WARNING: CPU: 0 PID: 30 at drivers/mmc/host/mxs-mmc.c:342 mxs_mmc_start_cmd+0x34c/0x378()
Modules linked in:
CPU: 0 PID: 30 Comm: kworker/u2:1 Not tainted 3.14.0-rc5 #8
Workqueue: kmmcd mmc_rescan
[<c0015420>] (unwind_backtrace) from [<c0012cb0>] (show_stack+0x10/0x14)
[<c0012cb0>] (show_stack) from [<c001daf8>] (warn_slowpath_common+0x6c/0x8c)
[<c001daf8>] (warn_slowpath_common) from [<c001db34>] (warn_slowpath_null+0x1c/0x24)
[<c001db34>] (warn_slowpath_null) from [<c0349478>] (mxs_mmc_start_cmd+0x34c/0x378)
[<c0349478>] (mxs_mmc_start_cmd) from [<c0338fa0>] (mmc_start_request+0xc4/0xf4)
[<c0338fa0>] (mmc_start_request) from [<c03390b4>] (mmc_wait_for_req+0x50/0x164)
[<c03390b4>] (mmc_wait_for_req) from [<c03405b8>] (mmc_app_send_scr+0x158/0x1c8)
[<c03405b8>] (mmc_app_send_scr) from [<c033ee1c>] (mmc_sd_setup_card+0x80/0x3c8)
[<c033ee1c>] (mmc_sd_setup_card) from [<c033f788>] (mmc_sd_init_card+0x124/0x66c)
[<c033f788>] (mmc_sd_init_card) from [<c033fd7c>] (mmc_attach_sd+0xac/0x174)
[<c033fd7c>] (mmc_attach_sd) from [<c033a658>] (mmc_rescan+0x25c/0x2d8)
[<c033a658>] (mmc_rescan) from [<c003597c>] (process_one_work+0x1b4/0x4ec)
[<c003597c>] (process_one_work) from [<c0035de4>] (worker_thread+0x130/0x464)
[<c0035de4>] (worker_thread) from [<c003c824>] (kthread+0xb4/0xd0)
[<c003c824>] (kthread) from [<c000f420>] (ret_from_fork+0x14/0x34)

The error is due to an invalid value in CSD register of a specific 2GB
micro SD card. The CSD version of this card is 1.0 but the TACC field
has the invalid value 0.

cid:0000005553442020000000000000583f
csd:00000032535a83bfedb7ffbf1680003f
date:08/2005
erase_size:512
fwrev:0x0
hwrev:0x0
manfid:0x000000
name:USD
oemid:0x0000
preferred_erase_size:4194304
scr:0225000000000000
serial:0x00000000
type:SD

Since the kernel is making use of this TACC field to calculate the SD
card timeout, an invalid value 0 leads to a warning at
mxs_ns_to_ssp_ticks() and later the following misleading error message
appears in a loop:

mxs-mmc 80010000.ssp: card claims to support voltages below defined range
mxs-mmc 80010000.ssp: no support for card's volts
mmc0: error -22 whilst initialising MMC card

This error is only found on this 2GB SD card on mxs platform.
On x86 this card works without any problems.

The following patch based on the work of Peter Chan and Otavio Salvador.
It catches the case that the determined timeout is still 0 and sets it
to a valid value.

Successful tested on a i.MX28 board.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
2014-04-22 07:06:39 -04:00
..
bus.c mmc: core: Remove unnecessary validations for bus_ops callbacks 2014-02-13 22:58:23 -05:00
bus.h
core.c mmc: core: Use maximum timeout values in case TACC field is zero 2014-04-22 07:06:39 -04:00
core.h mmc: core: Let mmc_set_signal_voltage take ocr as parameter 2013-10-30 20:26:26 -04:00
debugfs.c mmc: clarify DDR timing mode between SD-UHS and eMMC 2014-04-20 16:59:28 -04:00
host.c MMC highlights for 3.15: 2014-04-09 08:39:39 -07:00
host.h mmc: start removing enable / disable API 2012-03-27 12:20:03 -04:00
Kconfig mmc: core: Use MMC_UNSAFE_RESUME as default behavior 2014-02-13 22:58:15 -05:00
Makefile mmc: extend and rename cd-gpio helpers to handle more slot GPIO functions 2012-07-10 23:04:04 -04:00
mmc_ops.c mmc: core: Fixup busy detection for mmc switch operations 2014-02-23 10:40:38 -05:00
mmc_ops.h mmc: core: Restructure and simplify code for mmc sleep|awake 2013-05-26 14:23:17 -04:00
mmc.c mmc: Convert to use ATTRIBUTE_GROUPS 2014-04-22 07:06:38 -04:00
quirks.c mmc: sdio: add a quirk for broken SDIO_CCCR_INTx polling 2014-01-17 22:55:01 -05:00
sd_ops.c mmc: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required 2011-10-31 19:32:06 -04:00
sd_ops.h
sd.c mmc: Convert to use ATTRIBUTE_GROUPS 2014-04-22 07:06:38 -04:00
sd.h mmc: sd: add support for driver type selection 2011-05-24 23:53:24 -04:00
sdio_bus.c ACPI / bind: Redefine acpi_preset_companion() 2013-12-07 01:05:49 +01:00
sdio_bus.h
sdio_cis.c mmc: sdio: Change pr_warning to pr_warn_ratelimited 2012-07-22 15:25:48 -04:00
sdio_cis.h
sdio_io.c mmc: sdio: Use multiple scatter/gather list 2012-12-06 13:54:43 -05:00
sdio_irq.c mmc: sdio: add a quirk for broken SDIO_CCCR_INTx polling 2014-01-17 22:55:01 -05:00
sdio_ops.c mmc: sdio: Use multiple scatter/gather list 2012-12-06 13:54:43 -05:00
sdio_ops.h
sdio.c mmc: core: Collect common code for card ocr validation 2013-10-30 20:26:31 -04:00
slot-gpio.c mmc: Delay the card_event callback into the mmc_rescan worker 2014-04-22 07:06:36 -04:00