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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 09:41:26 +0200
commit0d69a8804134b22432e158a7760afe43d4a4f054 (patch)
treecb5c38f0299d07fe9c89b0d4c1d96b8e2b78ab20
parentb43ba21b3523101898a4ebb234fade7b1f58caae (diff)
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 1d9e00a00e9f..b0b9ceb0ab01 100644
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -412,6 +412,8 @@ 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.
@@ -424,6 +426,8 @@ 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 = {