lkml.org 
[lkml]   [2015]   [Dec]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/4] dmaengine: qcom_bam_dma: clear BAM interrupt only if it is rised
On Tue, Dec 01, 2015 at 11:14:57AM +0200, Stanimir Varbanov wrote:
> Currently we write BAM_IRQ_CLR register with zero even when no
> BAM_IRQ occured. This write has some bad side effects when the
> BAM instance is for the crypto engine. In case of crypto engine
> some of the BAM registers are xPU protected and they cannot be
> controlled by the driver.
>
> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
> ---
> drivers/dma/qcom_bam_dma.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/dma/qcom_bam_dma.c b/drivers/dma/qcom_bam_dma.c
> index dc9da477eb69..0f06f3b7a72b 100644
> --- a/drivers/dma/qcom_bam_dma.c
> +++ b/drivers/dma/qcom_bam_dma.c
> @@ -800,13 +800,17 @@ static irqreturn_t bam_dma_irq(int irq, void *data)
> if (srcs & P_IRQ)
> tasklet_schedule(&bdev->task);
>
> - if (srcs & BAM_IRQ)
> + if (srcs & BAM_IRQ) {
> clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
>
> - /* don't allow reorder of the various accesses to the BAM registers */
> - mb();
> + /*
> + * don't allow reorder of the various accesses to the BAM
> + * registers
> + */
> + mb();
>
> - writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
> + writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
> + }

Looks good. We shouldn't be accessing this unless there is actually an irq
shown in the srcs.


Thanks for catching this.


Reviewed-by: Andy Gross <agross@codeaurora.org>


\
 
 \ /
  Last update: 2015-12-01 18:41    [W:0.120 / U:0.656 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site