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authorBryan Freed <bfreed@chromium.org>2013-03-13 11:17:40 -0700
committerMark Brown <broonie@opensource.wolfsonmicro.com>2013-04-01 14:22:59 +0100
commitb0b36b861e434ee1c1a64cb39259e262f79af62e (patch)
tree57c741bdba95e18eab28fe82c2396b7b959c0f2a /drivers/spi
parent375981f2e14868be16cafbffd34a4f16a6ee01c6 (diff)
downloadop-kernel-dev-b0b36b861e434ee1c1a64cb39259e262f79af62e.zip
op-kernel-dev-b0b36b861e434ee1c1a64cb39259e262f79af62e.tar.gz
spi: Unlock a spinlock before calling into the controller driver.
spi_pump_messages() calls into a controller driver with unprepare_transfer_hardware() which is documented as "This may sleep". As in the prepare_transfer_hardware() call below, we should release the queue_lock spinlock before making the call. Rework the logic a bit to hold queue_lock to protect the 'busy' flag, then release it to call unprepare_transfer_hardware(). Signed-off-by: Bryan Freed <bfreed@chromium.org> Reviewed-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Doug Anderson <dianders@chromium.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index f996c600..5b96250 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -543,17 +543,16 @@ static void spi_pump_messages(struct kthread_work *work)
/* Lock queue and check for queue work */
spin_lock_irqsave(&master->queue_lock, flags);
if (list_empty(&master->queue) || !master->running) {
- if (master->busy && master->unprepare_transfer_hardware) {
- ret = master->unprepare_transfer_hardware(master);
- if (ret) {
- spin_unlock_irqrestore(&master->queue_lock, flags);
- dev_err(&master->dev,
- "failed to unprepare transfer hardware\n");
- return;
- }
+ if (!master->busy) {
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ return;
}
master->busy = false;
spin_unlock_irqrestore(&master->queue_lock, flags);
+ if (master->unprepare_transfer_hardware &&
+ master->unprepare_transfer_hardware(master))
+ dev_err(&master->dev,
+ "failed to unprepare transfer hardware\n");
return;
}
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