From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752640Ab2A0Ihi (ORCPT ); Fri, 27 Jan 2012 03:37:38 -0500 Received: from relmlor1.renesas.com ([210.160.252.171]:61069 "EHLO relmlor1.renesas.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751041Ab2A0Ihg (ORCPT ); Fri, 27 Jan 2012 03:37:36 -0500 X-IronPort-AV: E=Sophos;i="4.71,579,1320591600"; d="scan'208";a="65422132" Message-id: <4F22624E.2090201@renesas.com> Date: Fri, 27 Jan 2012 17:37:34 +0900 From: "Shimoda, Yoshihiro" User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:9.0) Gecko/20111222 Thunderbird/9.0.1 MIME-version: 1.0 To: Guennadi Liakhovetski Cc: linux-kernel@vger.kernel.org, linux-sh@vger.kernel.org, Vinod Koul , Magnus Damm , linux-mmc@vger.kernel.org, alsa-devel@alsa-project.org, linux-serial@vger.kernel.org, Paul Mundt Subject: Re: [PATCH 1/7 v2] dmaengine: add a simple dma library References: <1327589784-4287-1-git-send-email-g.liakhovetski@gmx.de> <1327589784-4287-2-git-send-email-g.liakhovetski@gmx.de> In-reply-to: <1327589784-4287-2-git-send-email-g.liakhovetski@gmx.de> Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Guennadi-san, 2012/01/26 23:56, Guennadi Liakhovetski wrote: > This patch adds a library of functions, helping to implement dmaengine > drivers for hardware, unable to handle scatter-gather lists natively. > The first version of this driver only supports memcpy and slave DMA > operation. > > Signed-off-by: Guennadi Liakhovetski > --- > > v2: > > 1. switch from using a tasklet to threaded IRQ, which allowed to I tested this driver on 2 environment, but it could not work correctly. - renesas_usbhs driver with shdma driver on the mackerel board - renesas_usbhs driver with experimental SUDMAC driver In this case, should we modify the renesas_usbhs driver? For reference, if I changed the threaded IRQ to tasklet, the 2 environment worked correctly: ============== diff --git a/drivers/dma/dma-simple.c b/drivers/dma/dma-simple.c index 49d8f7d..65a5170 100644 --- a/drivers/dma/dma-simple.c +++ b/drivers/dma/dma-simple.c @@ -715,16 +715,18 @@ static irqreturn_t chan_irq(int irq, void *dev) spin_lock(&schan->chan_lock); - ret = ops->chan_irq(schan, irq) ? IRQ_WAKE_THREAD : IRQ_NONE; + ret = ops->chan_irq(schan, irq) ? IRQ_HANDLED : IRQ_NONE; + if (ret == IRQ_HANDLED) + tasklet_schedule(&schan->tasklet); spin_unlock(&schan->chan_lock); return ret; } -static irqreturn_t chan_irqt(int irq, void *dev) +static void chan_irqt(unsigned long dev) { - struct dma_simple_chan *schan = dev; + struct dma_simple_chan *schan = (struct dma_simple_chan *)dev; const struct dma_simple_ops *ops = to_simple_dev(schan->dma_chan.device)->ops; struct dma_simple_desc *sdesc; @@ -744,15 +746,13 @@ static irqreturn_t chan_irqt(int irq, void *dev) spin_unlock_irq(&schan->chan_lock); simple_chan_ld_cleanup(schan, false); - - return IRQ_HANDLED; } int dma_simple_request_irq(struct dma_simple_chan *schan, int irq, unsigned long flags, const char *name) { - int ret = request_threaded_irq(irq, chan_irq, chan_irqt, - flags, name, schan); + int ret = request_irq(irq, chan_irq, flags, name, schan); + tasklet_init(&schan->tasklet, chan_irqt, (unsigned long)schan); schan->irq = ret < 0 ? ret : irq; diff --git a/include/linux/dma-simple.h b/include/linux/dma-simple.h index 5336674..beb1489 100644 --- a/include/linux/dma-simple.h +++ b/include/linux/dma-simple.h @@ -68,6 +68,7 @@ struct dma_simple_chan { int id; /* Raw id of this channel */ int irq; /* Channel IRQ */ enum dma_simple_pm_state pm_state; + struct tasklet_struct tasklet; }; /** ============== Best regards, Yoshihiro Shimoda