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authorRasmus Villemoes <linux@rasmusvillemoes.dk>2019-12-04 09:54:46 +0100
committerUlf Hansson <ulf.hansson@linaro.org>2019-12-16 12:25:26 +0100
commit8b6dc6b2d60221e90703babbc141f063b8a07e72 (patch)
treea47319b6dea2ba42f95f2f5b0503260cbd5593fc /drivers/mmc/host/sdhci-of-esdhc.c
parentmmc: mediatek: fix CMD_TA to 2 for MT8173 HS200/HS400 mode (diff)
downloadlinux-8b6dc6b2d60221e90703babbc141f063b8a07e72.tar.xz
linux-8b6dc6b2d60221e90703babbc141f063b8a07e72.zip
mmc: sdhci-of-esdhc: Revert "mmc: sdhci-of-esdhc: add erratum A-009204 support"
This reverts commit 5dd195522562542bc6ebe6e7bd47890d8b7ca93c. 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>
Diffstat (limited to 'drivers/mmc/host/sdhci-of-esdhc.c')
-rw-r--r--drivers/mmc/host/sdhci-of-esdhc.c3
1 files changed, 0 insertions, 3 deletions
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 5cca3fa4610b..7f87a90bf56a 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -764,9 +764,6 @@ static void esdhc_reset(struct sdhci_host *host, u8 mask)
sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
- if (of_find_compatible_node(NULL, NULL, "fsl,p2020-esdhc"))
- mdelay(5);
-
if (mask & SDHCI_RESET_ALL) {
val = sdhci_readl(host, ESDHC_TBCTL);
val &= ~ESDHC_TB_EN;