From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-out.m-online.net (mail-out.m-online.net [212.18.0.9]) by ozlabs.org (Postfix) with ESMTP id 815B8B70E9 for ; Tue, 28 Sep 2010 22:25:29 +1000 (EST) From: Ilya Yanok To: linuxppc-dev@lists.ozlabs.org, wd@denx.de, dzu@denx.de, vlad@emcraft.com Subject: [PATCH 2/3] mpc512x_dma: fix the hanged transfer issue Date: Tue, 28 Sep 2010 14:24:55 +0200 Message-Id: <1285676696-5358-3-git-send-email-yanok@emcraft.com> In-Reply-To: <1285676696-5358-1-git-send-email-yanok@emcraft.com> References: <1285676696-5358-1-git-send-email-yanok@emcraft.com> Cc: Piotr Ziecik , Ilya Yanok List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Current code clears interrupt active status _after_ submiting 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 submited and for current channel only. Signed-off-by: Ilya Yanok Cc: Piotr Ziecik --- drivers/dma/mpc512x_dma.c | 9 +++------ 1 files changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/dma/mpc512x_dma.c b/drivers/dma/mpc512x_dma.c index 1bc04aa..0717527 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); -- 1.7.2.3