This is a note to let you know that I've just added the patch titled
dmaengine: qcom_hidma: check pending interrupts
to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: dmaengine-qcom_hidma-check-pending-interrupts.patch and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Fri Mar 16 15:11:08 CET 2018
From: Sinan Kaya okaya@codeaurora.org Date: Tue, 14 Nov 2017 09:55:01 -0500 Subject: dmaengine: qcom_hidma: check pending interrupts
From: Sinan Kaya okaya@codeaurora.org
[ Upstream commit 38680bc6b1e3592bc9e18adc1d6e259667df27ce ]
Driver is missing the interrupts if two requests are queued up at the same time as the interrupt handler is servicing a request that was just delivered.
The ISR clears the interrupt at the end but it could be clearing the interrupt for an outstanding event. Therefore, second interrupt never arrives.
Clear the interrupt first and then check for completions.
Also, make sure that request start and interrupt clear do not overlap in time by using a spinlock.
Signed-off-by: Sinan Kaya okaya@codeaurora.org Signed-off-by: Vinod Koul vinod.koul@intel.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/dma/qcom/hidma_ll.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
--- a/drivers/dma/qcom/hidma_ll.c +++ b/drivers/dma/qcom/hidma_ll.c @@ -393,6 +393,8 @@ static int hidma_ll_reset(struct hidma_l */ static void hidma_ll_int_handler_internal(struct hidma_lldev *lldev, int cause) { + unsigned long irqflags; + if (cause & HIDMA_ERR_INT_MASK) { dev_err(lldev->dev, "error 0x%x, disabling...\n", cause); @@ -410,6 +412,10 @@ static void hidma_ll_int_handler_interna return; }
+ spin_lock_irqsave(&lldev->lock, irqflags); + writel_relaxed(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG); + spin_unlock_irqrestore(&lldev->lock, irqflags); + /* * Fine tuned for this HW... * @@ -421,9 +427,6 @@ static void hidma_ll_int_handler_interna * Try to consume as many EVREs as possible. */ hidma_handle_tre_completion(lldev); - - /* We consumed TREs or there are pending TREs or EVREs. */ - writel_relaxed(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG); }
irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
Patches currently in stable-queue which might be from okaya@codeaurora.org are
queue-4.15/dmaengine-qcom_hidma-check-pending-interrupts.patch