From 0cf7399e340d8be431a970094abaebb40cac55bb Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Mon, 20 Mar 2017 19:50:29 +0200 Subject: [PATCH] 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 Signed-off-by: Ulf Hansson Tested-by: Ludovic Desroches Signed-off-by: Ben Hutchings --- drivers/mmc/host/sdhci.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 9f68b82effd7..99bc62e9b930 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1150,7 +1150,9 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock) return; } timeout--; - mdelay(1); + spin_unlock_irq(&host->lock); + usleep_range(900, 1100); + spin_lock_irq(&host->lock); } clk |= SDHCI_CLOCK_CARD_EN; -- 2.39.2