sdhci-omap: additional PM issue since 5.16

[David Owens <daowens01@gmail.com>]

Hello,

I have a AM574x system and encountered an eMMC regression when upgrading from 5.15 to 6.1.38.  The eMMC is using mmc-hs200 powered at 1.8v.  Reads from /dev/mmcblk1boot0 will return expected data except when a delay of several seconds is inserted between reads.  With a delay between reads, the read will occasionally (~50% of the time) return garbage data.  Using hexdump, I was able to determine that the "bad" data is actually coming from /dev/mmcblk1, not /dev/mmcblk1boot0.  The same thing happens when reading from /dev/mmcblk1boot1.

Much like a previous report in the linux-omap mailing list [1], I too was able to correct the regression by reverting the commit "mmc: sdhci-omap: Allow SDIO card power off and enable aggressive PM" [2].  Unlike the previous report, applying the sdhci-omap patch [3] did not resolve my issue.  Only reverting the original commit allowed for reliable reads from /dev/mmcblk1boot0.  I also don't see the same I/O errors mentioned in the previous posting.  Reads always succeed and return the correct amount of data, its just from the wrong device.

[1] https://lore.kernel.org/all/2e5f1997-564c-44e4-b357-6343e0dae7ab@smile.fr/

[2] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3edf588e7fe00e90d1dc7fb9e599861b2c2cf442

[3] https://lore.kernel.org/linux-omap/20240315234444.816978-1-romain.naour@smile.fr/T/#u

Regards,

Dave