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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2018-05-04 16:24:44 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-06-05 16:26:46 -0400 |
| commit | 56f0ddadcea9dc264f1c8eed6cc984071b141554 (patch) | |
| tree | 2da35ce3b963091950a542f30ce4c54a463aa1d5 /drivers/ide/ide-io.c | |
| parent | 820ec411e67c8dab645fb7e180875d619b6ab7e7 (diff) | |
| download | linux-56f0ddadcea9dc264f1c8eed6cc984071b141554.tar.gz linux-56f0ddadcea9dc264f1c8eed6cc984071b141554.tar.bz2 linux-56f0ddadcea9dc264f1c8eed6cc984071b141554.zip | |
ide: Handle irq disabling consistently
ide_timer_expiry() disables interrupt at function entry when acquiring
hwif->lock. Before disabling the device interrupt it unlocks hwif->lock,
but interrupts stay disabled. After the call to disable_irq() interrupts
are disabled again, which is a pointless exercise.
After the device irq handler has been invoked with interrupts disabled,
hwif->lock is acquired again with spin_lock_irq() because the device irq
handler might have reenabled interrupts. This is not documented and
confusing for the casual reader.
Remove the redundant local_irq_disable() and add a comment which explains
why hwif->lock has to be reacquired with spin_lock_irq().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/ide/ide-io.c')
| -rw-r--r-- | drivers/ide/ide-io.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index 6f25da56a169..a444bad7a2aa 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -659,8 +659,7 @@ void ide_timer_expiry (struct timer_list *t) spin_unlock(&hwif->lock); /* disable_irq_nosync ?? */ disable_irq(hwif->irq); - /* local CPU only, as if we were handling an interrupt */ - local_irq_disable(); + if (hwif->polling) { startstop = handler(drive); } else if (drive_is_ready(drive)) { @@ -679,6 +678,7 @@ void ide_timer_expiry (struct timer_list *t) startstop = ide_error(drive, "irq timeout", hwif->tp_ops->read_status(hwif)); } + /* Disable interrupts again, `handler' might have enabled it */ spin_lock_irq(&hwif->lock); enable_irq(hwif->irq); if (startstop == ide_stopped && hwif->polling == 0) { |