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authorAdrian Hunter <adrian.hunter@intel.com>2017-03-20 19:50:30 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-03-30 09:44:07 +0200
commitce6c155ada08872d3b80aaa9b4c13391397436fb (patch)
tree93f4931f844b0eb3f12594fb7c47792e32a69b8e
parentf89c8a5007b27107344417798f52ff694fb1b081 (diff)
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mmc: sdhci-pci: Do not disable interrupts in sdhci_intel_set_power
commit 027fb89e61054b4aedd962adb3e2003dec78a716 upstream. 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> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 1a72d32af07f..e977048a8428 100644
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -452,6 +452,8 @@ 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.
@@ -464,6 +466,8 @@ 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 = {