Alek Du b704441e38 mmc: sdhci: fix the timeout check window for clock and reset ... We observed some premature timeouts on a virtualization platform, the log is like this: case 1: [159525.255629] mmc1: Internal clock never stabilised. [159525.255818] mmc1: sdhci: ============ SDHCI REGISTER DUMP =========== [159525.256049] mmc1: sdhci: Sys addr: 0x00000000 | Version: 0x00001002 ... [159525.257205] mmc1: sdhci: Wake-up: 0x00000000 | Clock: 0x0000fa03 From the clock control register dump, we are pretty sure the clock was stablized. case 2: [ 914.550127] mmc1: Reset 0x2 never completed. [ 914.550321] mmc1: sdhci: ============ SDHCI REGISTER DUMP =========== [ 914.550608] mmc1: sdhci: Sys addr: 0x00000010 | Version: 0x00001002 After checking the sdhci code, we found the timeout check actually has a little window that the CPU can be scheduled out and when it comes back, the original time set or check is not valid. Fixes: 5a436cc0af ("mmc: sdhci: Optimize delay loops") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Alek Du <alek.du@intel.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>		2018-12-06 11:22:00 +01:00
..
core	mmc: core: use mrq->sbc when sending CMD23 for RPMB	2018-12-04 10:12:12 +01:00
host	mmc: sdhci: fix the timeout check window for clock and reset	2018-12-06 11:22:00 +01:00
Kconfig	mmc: core: Remove option not to use blk-mq	2017-12-11 12:55:02 +01:00
Makefile	mmc: Kconfig: downgrade CONFIG_MMC_DEBUG for host drivers only	2017-08-30 14:01:34 +02:00