Commit d4b6af2e authored by Chris Blair's avatar Chris Blair Committed by Linus Walleij
Browse files

spi/pl022: move device disable to workqueue thread 



Moves the disabling of the device and clocks to the same thread in
which the device and clocks are enabled. This avoids SMP issues where
the device can be enabled for a transfer by one thread and then
disabled by the completion of the previous transfer in another thread.

Reviewed-by: default avatarViresh Kumar <viresh.kumar@st.com>
Signed-off-by: default avatarChris Blair <chris.blair@stericsson.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 4ca9fb46

drivers/spi/spi-pl022.c

+16 −9
Original line number Diff line number Diff line
@@ -512,8 +512,6 @@ static void giveback(struct pl022 *pl022) 
	msg->state = NULL;

	if (msg->complete)

		msg->complete(msg->context);

	/* This message is completed, so let's turn off the clocks & power */

	pm_runtime_put(&pl022->adev->dev);

}



/**
@@ -1509,14 +1507,18 @@ static void pump_messages(struct work_struct *work) 
	struct pl022 *pl022 =

		container_of(work, struct pl022, pump_messages);

	unsigned long flags;

	bool was_busy = false;



	/* Lock queue and check for queue work */

	spin_lock_irqsave(&pl022->queue_lock, flags);

	if (list_empty(&pl022->queue) || !pl022->running) {

		if (pl022->busy)

			pm_runtime_put(&pl022->adev->dev);

		pl022->busy = false;

		spin_unlock_irqrestore(&pl022->queue_lock, flags);

		return;

	}



	/* Make sure we are not already running a message */

	if (pl022->cur_msg) {

		spin_unlock_irqrestore(&pl022->queue_lock, flags);
@@ -1527,6 +1529,9 @@ static void pump_messages(struct work_struct *work) 
	    list_entry(pl022->queue.next, struct spi_message, queue);



	list_del_init(&pl022->cur_msg->queue);

	if (pl022->busy)

		was_busy = true;

	else

		pl022->busy = true;

	spin_unlock_irqrestore(&pl022->queue_lock, flags);
@@ -1537,12 +1542,14 @@ static void pump_messages(struct work_struct *work) 


	/* Setup the SPI using the per chip configuration */

	pl022->cur_chip = spi_get_ctldata(pl022->cur_msg->spi);

	if (!was_busy)

		/*

		 * We enable the core voltage and clocks here, then the clocks

	 * and core will be disabled when giveback() is called in each method

	 * (poll/interrupt/DMA)

		 * and core will be disabled when this workqueue is run again

		 * and there is no more work to be done.

		 */

		pm_runtime_get_sync(&pl022->adev->dev);



	restore_state(pl022);

	flush(pl022);

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