mirror of https://github.com/hak5/openwrt.git
48 lines
1.5 KiB
Diff
48 lines
1.5 KiB
Diff
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From: Mark Brown <broonie@kernel.org>
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Date: Tue, 9 Dec 2014 19:46:56 +0000
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Subject: [PATCH] spi: Check to see if the device is processing a message
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before we idle
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cur_msg is updated under the queue lock and holds the message we are
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currently processing. Since currently we only ever do removals in the
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pump kthread it doesn't matter in what order we do things but we want
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to be able to push things out from the submitting thread so pull the
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check to see if we're currently handling a message before we check to
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see if the queue is idle.
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Signed-off-by: Mark Brown <broonie@kernel.org>
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---
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--- a/drivers/spi/spi.c
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+++ b/drivers/spi/spi.c
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@@ -891,8 +891,16 @@ static void spi_pump_messages(struct kth
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bool was_busy = false;
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int ret;
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- /* Lock queue and check for queue work */
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+ /* Lock queue */
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spin_lock_irqsave(&master->queue_lock, flags);
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+
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+ /* Make sure we are not already running a message */
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+ if (master->cur_msg) {
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+ spin_unlock_irqrestore(&master->queue_lock, flags);
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+ return;
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+ }
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+
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+ /* Check if the queue is idle */
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if (list_empty(&master->queue) || !master->running) {
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if (!master->busy) {
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spin_unlock_irqrestore(&master->queue_lock, flags);
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@@ -916,11 +924,6 @@ static void spi_pump_messages(struct kth
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return;
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}
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- /* Make sure we are not already running a message */
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- if (master->cur_msg) {
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- spin_unlock_irqrestore(&master->queue_lock, flags);
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- return;
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- }
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/* Extract head of queue */
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master->cur_msg =
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list_first_entry(&master->queue, struct spi_message, queue);
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