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@xxxxxxxxxx>
> ---
> 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@xxxxxxxxxxxxxx>
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