Commit b0b36b86 authored Mar 13, 2013 by Bryan Freed Committed by Mark Brown Apr 01, 2013

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>

parent 375981f2

drivers/spi/spi.c

+7 −8

Original line number	Diff line number	Diff line
		@@ -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) {
		if (!master->busy) {
		spin_unlock_irqrestore(&master->queue_lock, flags);
		dev_err(&master->dev,
		"failed to unprepare transfer hardware\n");
		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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