Douglas Anderson 9d5dcefb7b mmc: sdhci-msm: Add retries when all tuning phases are found valid ... As the comments in this patch say, if we tune and find all phases are valid it's _almost_ as bad as no phases being found valid. Probably all phases are not really reliable but we didn't detect where the unreliable place is. That means we'll essentially be guessing and hoping we get a good phase. This is not just a problem in theory. It was causing real problems on a real board. On that board, most often phase 10 is found as the only invalid phase, though sometimes 10 and 11 are invalid and sometimes just 11. Some percentage of the time, however, all phases are found to be valid. When this happens, the current logic will decide to use phase 11. Since phase 11 is sometimes found to be invalid, this is a bad choice. Sure enough, when phase 11 is picked we often get mmc errors later in boot. I have seen cases where all phases were found to be valid 3 times in a row, so increase the retry count to 10 just to be extra sure. Fixes: 415b5a75da ("mmc: sdhci-msm: Add platform_execute_tuning implementation") Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Link: https://lore.kernel.org/r/20200827075809.1.If179abf5ecb67c963494db79c3bc4247d987419b@changeid Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>		2020-09-07 08:57:44 +02:00
..
core	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
host	mmc: sdhci-msm: Add retries when all tuning phases are found valid	2020-09-07 08:57:44 +02:00
Kconfig	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00