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authorAdrian Hunter <adrian.hunter@intel.com>2017-03-20 19:50:29 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-03-30 09:44:07 +0200
commitf89c8a5007b27107344417798f52ff694fb1b081 (patch)
tree794973f97f7a7df822dad476959432133922d9ee
parentb821a0a5fde92add670f877f29e65e8ad7b05b1a (diff)
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mmc: sdhci: Do not disable interrupts while waiting for clock
commit e2ebfb2142acefecc2496e71360f50d25726040b upstream. Disabling interrupts for even a millisecond can cause problems for some devices. That can happen when sdhci changes clock frequency because it waits for the clock to become stable under a spin lock. 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.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 0def99590d16..d0819d18ad08 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1362,7 +1362,9 @@ void sdhci_enable_clk(struct sdhci_host *host, u16 clk)
return;
}
timeout--;
- mdelay(1);
+ spin_unlock_irq(&host->lock);
+ usleep_range(900, 1100);
+ spin_lock_irq(&host->lock);
}
clk |= SDHCI_CLOCK_CARD_EN;