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authorAdrian Hunter <adrian.hunter@intel.com>2017-03-20 19:50:30 +0200
committerUlf Hansson <ulf.hansson@linaro.org>2017-03-23 09:24:42 +0100
commit027fb89e61054b4aedd962adb3e2003dec78a716 (patch)
tree23354ce850fb69f150c086233d42d40bfcdc1e7f /drivers/mmc
parente2ebfb2142acefecc2496e71360f50d25726040b (diff)
downloadlinux-027fb89e61054b4aedd962adb3e2003dec78a716.tar.bz2
mmc: sdhci-pci: Do not disable interrupts in sdhci_intel_set_power
Disabling interrupts for even a millisecond can cause problems for some devices. That can happen when Intel host controllers wait for the present state to propagate. The spin lock is not necessary here. Anything that is racing with changes to the I/O state is already broken. The mmc core already provides synchronization via "claiming" the host. Although the spin lock probably should be removed from the code paths that lead to this point, such a patch would touch too much code to be suitable for stable trees. Consequently, for this patch, just drop the spin lock while waiting. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/sdhci-pci-core.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index 982b3e349426..86560d590786 100644
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -451,6 +451,8 @@ static void sdhci_intel_set_power(struct sdhci_host *host, unsigned char mode,
if (mode == MMC_POWER_OFF)
return;
+ spin_unlock_irq(&host->lock);
+
/*
* Bus power might not enable after D3 -> D0 transition due to the
* present state not yet having propagated. Retry for up to 2ms.
@@ -463,6 +465,8 @@ static void sdhci_intel_set_power(struct sdhci_host *host, unsigned char mode,
reg |= SDHCI_POWER_ON;
sdhci_writeb(host, reg, SDHCI_POWER_CONTROL);
}
+
+ spin_lock_irq(&host->lock);
}
static const struct sdhci_ops sdhci_intel_byt_ops = {