• Jisheng Zhang's avatar
    mmc: sdhci-pxav3: fix race between runtime pm and irq · 44baa458
    Jisheng Zhang authored
    commit 3bb10f60 upstream.
    
    This patch is to fix a race condition that may cause an unhandled irq,
    which results in big sdhci interrupt numbers and endless "mmc1: got irq
    while runtime suspended" msgs before v3.15.
    
    Consider following scenario:
    
          CPU0                            CPU1
                                  sdhci_pxav3_runtime_suspend()
                                   spin_lock_irqsave(&host->lock, flags);
     sdhci_irq()
      spining on the &host->lock
                                   host->runtime_suspended = true;
                                   spin_unlock_irqrestore(&host->lock, flags);
      get the &host->lock
      runtime_suspended is true now
      return IRQ_NONE;
    
    Fix this race by using the core sdhci.c supplied sdhci_runtime_suspend_host()
    in runtime suspend hook which will disable card interrupts. We also use the
    sdhci_runtime_resume_host() in the runtime resume hook accordingly.
    Signed-off-by: default avatarJisheng Zhang <jszhang@marvell.com>
    Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
    [ luis: backported to 3.16: adjusted context ]
    Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
    44baa458
sdhci-pxav3.c 12.2 KB