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Javi Merino authored
If two requests have been submitted and one of them is running, if you call pl330_chan_ctrl(ch_id, PL330_OP_START), there's a window of time between the spin_lock_irqsave() and the _state() check in which the running transaction may finish. In that case, we don't receive the interrupt (because they are disabled), but _start() sees that the DMA is stopped, so it starts it. The problem is that it sends the transaction that has just finished again, because pl330_update() hasn't mark it as done yet. This patch fixes this race condition by not calling _start() if the DMA is already executing transactions. When interrupts are reenabled, pl330_update() will call _start(). Reference: <1317892206-3600-1-git-send-email-javi.merino@arm.com> Signed-off-by:
Javi Merino <javi.merino@arm.com> Acked-by:
Jassi Brar <jassi.brar@samsung.com> Signed-off-by:
Russell King <rmk+kernel@arm.linux.org.uk>
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