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| author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2019-12-04 11:54:46 +0300 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2019-12-16 14:25:26 +0300 |
| commit | 8b6dc6b2d60221e90703babbc141f063b8a07e72 (patch) | |
| tree | a47319b6dea2ba42f95f2f5b0503260cbd5593fc /drivers/mmc/host | |
| parent | 8f34e5bd7024d1ffebddd82d7318b1be17be9e9a (diff) | |
| download | linux-8b6dc6b2d60221e90703babbc141f063b8a07e72.tar.xz | |
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')
| -rw-r--r-- | drivers/mmc/host/sdhci-of-esdhc.c | 3 |
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; |