From: Ilya Yanok Date: Tue, 26 Oct 2010 23:52:56 +0000 (+0200) Subject: powerpc/512x: fix the hanged dma transfer issue X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=2862559e8a1e7c47bb3003f0edbc9db9009dc32b;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git powerpc/512x: fix the hanged dma transfer issue Current code clears interrupt active status _after_ submitting new transfers. This leaves a possibility of clearing the interrupt for this new transfer (if it is triggered fast enough) and thus lose this interrupt. We want to clear interrupt active status _before_ new transfers is submitted and for current channel only. Signed-off-by: Ilya Yanok Acked-by: Wolfgang Denk Signed-off-by: Grant Likely --- diff --git a/drivers/dma/mpc512x_dma.c b/drivers/dma/mpc512x_dma.c index 1bc04aa27b14..071752727718 100644 --- a/drivers/dma/mpc512x_dma.c +++ b/drivers/dma/mpc512x_dma.c @@ -276,6 +276,9 @@ static void mpc_dma_irq_process(struct mpc_dma *mdma, u32 is, u32 es, int off) spin_lock(&mchan->lock); + out_8(&mdma->regs->dmacint, ch + off); + out_8(&mdma->regs->dmacerr, ch + off); + /* Check error status */ if (es & (1 << ch)) list_for_each_entry(mdesc, &mchan->active, node) @@ -309,12 +312,6 @@ static irqreturn_t mpc_dma_irq(int irq, void *data) mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmaintl), in_be32(&mdma->regs->dmaerrl), 0); - /* Ack interrupt on all channels */ - out_be32(&mdma->regs->dmainth, 0xFFFFFFFF); - out_be32(&mdma->regs->dmaintl, 0xFFFFFFFF); - out_be32(&mdma->regs->dmaerrh, 0xFFFFFFFF); - out_be32(&mdma->regs->dmaerrl, 0xFFFFFFFF); - /* Schedule tasklet */ tasklet_schedule(&mdma->tasklet);