mmc: sdhci-iproc: Set NO_HISPD bit to fix HS50 data hold time problem
authorTrac Hoang <trac.hoang@broadcom.com>
Thu, 9 May 2019 17:24:27 +0000 (10:24 -0700)
committerUlf Hansson <ulf.hansson@linaro.org>
Wed, 15 May 2019 11:52:05 +0000 (13:52 +0200)
commitec0970e0a1b2c807c908d459641a9f9a1be3e130
tree42633be1d06de57cd3113531b800d9c33cafedb1
parentb7dfa695afc40d5396ed84b9f25aa3754de23e39
mmc: sdhci-iproc: Set NO_HISPD bit to fix HS50 data hold time problem

The iproc host eMMC/SD controller hold time does not meet the
specification in the HS50 mode.  This problem can be mitigated
by disabling the HISPD bit; thus forcing the controller output
data to be driven on the falling clock edges rather than the
rising clock edges.

Stable tag (v4.12+) chosen to assist stable kernel maintainers so that
the change does not produce merge conflicts backporting to older kernel
versions. In reality, the timing bug existed since the driver was first
introduced but there is no need for this driver to be supported in kernel
versions that old.

Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Trac Hoang <trac.hoang@broadcom.com>
Signed-off-by: Scott Branden <scott.branden@broadcom.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
drivers/mmc/host/sdhci-iproc.c