mmc: sdhci-of-esdhc: Revert "mmc: sdhci-of-esdhc: add erratum A-009204 support"
This reverts commit 5dd19552. First, the fix seems to be plain wrong, since the erratum suggests waiting 5ms before setting setting SYSCTL[RSTD], but this msleep() happens after the call of sdhci_reset() which is where that bit gets set (if SDHCI_RESET_DATA is in mask). Second, walking the whole device tree to figure out if some node has a "fsl,p2020-esdhc" compatible string is hugely expensive - about 70 to 100 us on our mpc8309 board. Walking the device tree is done under a raw_spin_lock, so this is obviously really bad on an -rt system, and a waste of time on all. In fact, since esdhc_reset() seems to get called around 100 times per second, that mpc8309 now spends 0.8% of its time determining that it is not a p2020. Whether those 100 calls/s are normal or due to some other bug or misconfiguration, regularly hitting a 100 us non-preemptible window is unacceptable. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20191204085447.27491-1-linux@rasmusvillemoes.dk Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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