From patchwork Mon Jan 31 12:22:29 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anatolij Gustschin X-Patchwork-Id: 519331 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p0VCIjo3007581 for ; Mon, 31 Jan 2011 12:21:42 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754868Ab1AaMVk (ORCPT ); Mon, 31 Jan 2011 07:21:40 -0500 Received: from mail-out.m-online.net ([212.18.0.10]:42215 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753341Ab1AaMVk (ORCPT ); Mon, 31 Jan 2011 07:21:40 -0500 Received: from frontend1.mail.m-online.net (frontend1.mail.intern.m-online.net [192.168.8.180]) by mail-out.m-online.net (Postfix) with ESMTP id E237E186DECD; Mon, 31 Jan 2011 13:21:37 +0100 (CET) X-Auth-Info: S6Svbgx59BfzRseBps1+coXZ4hL+E/fvFzGn8Z81vVA= Received: from localhost (p4FE3DF32.dip.t-dialin.net [79.227.223.50]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mail.mnet-online.de (Postfix) with ESMTPSA id C29961C0010F; Mon, 31 Jan 2011 13:21:37 +0100 (CET) From: Anatolij Gustschin To: linux-media@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Guennadi Liakhovetski , Dan Williams , Detlev Zundel , Markus Niebel Subject: [PATCH 2/2 v2] dma: ipu_idmac: do not lose valid received data in the irq handler Date: Mon, 31 Jan 2011 13:22:29 +0100 Message-Id: <1296476549-10421-1-git-send-email-agust@denx.de> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1296031789-1721-3-git-send-email-agust@denx.de> References: <1296031789-1721-3-git-send-email-agust@denx.de> Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Mon, 31 Jan 2011 12:21:42 +0000 (UTC) diff --git a/drivers/dma/ipu/ipu_idmac.c b/drivers/dma/ipu/ipu_idmac.c index cb26ee9..c1a125e 100644 --- a/drivers/dma/ipu/ipu_idmac.c +++ b/drivers/dma/ipu/ipu_idmac.c @@ -1145,29 +1145,6 @@ static int ipu_disable_channel(struct idmac *idmac, struct idmac_channel *ichan, reg = idmac_read_icreg(ipu, IDMAC_CHA_EN); idmac_write_icreg(ipu, reg & ~chan_mask, IDMAC_CHA_EN); - /* - * Problem (observed with channel DMAIC_7): after enabling the channel - * and initialising buffers, there comes an interrupt with current still - * pointing at buffer 0, whereas it should use buffer 0 first and only - * generate an interrupt when it is done, then current should already - * point to buffer 1. This spurious interrupt also comes on channel - * DMASDC_0. With DMAIC_7 normally, is we just leave the ISR after the - * first interrupt, there comes the second with current correctly - * pointing to buffer 1 this time. But sometimes this second interrupt - * doesn't come and the channel hangs. Clearing BUFx_RDY when disabling - * the channel seems to prevent the channel from hanging, but it doesn't - * prevent the spurious interrupt. This might also be unsafe. Think - * about the IDMAC controller trying to switch to a buffer, when we - * clear the ready bit, and re-enable it a moment later. - */ - reg = idmac_read_ipureg(ipu, IPU_CHA_BUF0_RDY); - idmac_write_ipureg(ipu, 0, IPU_CHA_BUF0_RDY); - idmac_write_ipureg(ipu, reg & ~(1UL << channel), IPU_CHA_BUF0_RDY); - - reg = idmac_read_ipureg(ipu, IPU_CHA_BUF1_RDY); - idmac_write_ipureg(ipu, 0, IPU_CHA_BUF1_RDY); - idmac_write_ipureg(ipu, reg & ~(1UL << channel), IPU_CHA_BUF1_RDY); - spin_unlock_irqrestore(&ipu->lock, flags); return 0; @@ -1246,33 +1223,6 @@ static irqreturn_t idmac_interrupt(int irq, void *dev_id) /* Other interrupts do not interfere with this channel */ spin_lock(&ichan->lock); - if (unlikely(chan_id != IDMAC_SDC_0 && chan_id != IDMAC_SDC_1 && - ((curbuf >> chan_id) & 1) == ichan->active_buffer && - !list_is_last(ichan->queue.next, &ichan->queue))) { - int i = 100; - - /* This doesn't help. See comment in ipu_disable_channel() */ - while (--i) { - curbuf = idmac_read_ipureg(&ipu_data, IPU_CHA_CUR_BUF); - if (((curbuf >> chan_id) & 1) != ichan->active_buffer) - break; - cpu_relax(); - } - - if (!i) { - spin_unlock(&ichan->lock); - dev_dbg(dev, - "IRQ on active buffer on channel %x, active " - "%d, ready %x, %x, current %x!\n", chan_id, - ichan->active_buffer, ready0, ready1, curbuf); - return IRQ_NONE; - } else - dev_dbg(dev, - "Buffer deactivated on channel %x, active " - "%d, ready %x, %x, current %x, rest %d!\n", chan_id, - ichan->active_buffer, ready0, ready1, curbuf, i); - } - if (unlikely((ichan->active_buffer && (ready1 >> chan_id) & 1) || (!ichan->active_buffer && (ready0 >> chan_id) & 1) )) {