From: Wolfram Sang <w.sang@pengutronix.de>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: dedekind1@gmail.com, thierry.nolf.barco@gmail.com,
Huang Shijie <b32955@freescale.com>,
linux-mtd@lists.infradead.org,
linux-arm-kernel@lists.infradead.org, LW@KARO-electronics.de
Subject: Re: [PATCH v7 1/3] MTD : add the common code for GPMI-NFC controller driver
Date: Wed, 29 Jun 2011 14:49:02 +0200 [thread overview]
Message-ID: <20110629124902.GI1992@pengutronix.de> (raw)
In-Reply-To: <20110629124214.GN21898@n2100.arm.linux.org.uk>
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On Wed, Jun 29, 2011 at 01:42:14PM +0100, Russell King - ARM Linux wrote:
> On Wed, Jun 29, 2011 at 02:29:42PM +0200, Wolfram Sang wrote:
> >
> > > > Still, the problem exists: When a second channel GPMI channel is
> > > > requested, dmaengine will return -EBUSY, because the DMAIRQ is already
> > > > taken.
> > > >
> > > Yes, we should change the DMA code, it is a DMA bug.
> > > I ever submitted a patch about the issue:
> > > http://patchwork.ozlabs.org/patch/87145/
> >
> > That approach was rejected because it would register the same handler
> > n-times where one time would do. Your other approach puts too much
> > mach-specific details into the driver IMO and probably won't scale very
> > well. Maybe we should add something to the private dma_data (like flags
> > indicating SHARED) and then do some refcounting?
>
> Why not just request the interrupt once when the mxs-dma stuff probes,
> rather than requesting it every time a channel is allocated?
It is only the NAND DMA channels which share one dma-irq. All other
channels have a seperate interrupt.
--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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WARNING: multiple messages have this Message-ID (diff)
From: w.sang@pengutronix.de (Wolfram Sang)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v7 1/3] MTD : add the common code for GPMI-NFC controller driver
Date: Wed, 29 Jun 2011 14:49:02 +0200 [thread overview]
Message-ID: <20110629124902.GI1992@pengutronix.de> (raw)
In-Reply-To: <20110629124214.GN21898@n2100.arm.linux.org.uk>
On Wed, Jun 29, 2011 at 01:42:14PM +0100, Russell King - ARM Linux wrote:
> On Wed, Jun 29, 2011 at 02:29:42PM +0200, Wolfram Sang wrote:
> >
> > > > Still, the problem exists: When a second channel GPMI channel is
> > > > requested, dmaengine will return -EBUSY, because the DMAIRQ is already
> > > > taken.
> > > >
> > > Yes, we should change the DMA code, it is a DMA bug.
> > > I ever submitted a patch about the issue:
> > > http://patchwork.ozlabs.org/patch/87145/
> >
> > That approach was rejected because it would register the same handler
> > n-times where one time would do. Your other approach puts too much
> > mach-specific details into the driver IMO and probably won't scale very
> > well. Maybe we should add something to the private dma_data (like flags
> > indicating SHARED) and then do some refcounting?
>
> Why not just request the interrupt once when the mxs-dma stuff probes,
> rather than requesting it every time a channel is allocated?
It is only the NAND DMA channels which share one dma-irq. All other
channels have a seperate interrupt.
--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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next prev parent reply other threads:[~2011-06-29 12:49 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-29 8:24 [PATCH v7 0/3] add the GPMI controller driver for IMX23/IMX28 Huang Shijie
2011-06-29 8:24 ` Huang Shijie
2011-06-29 8:24 ` Huang Shijie
2011-06-29 8:24 ` Huang Shijie
2011-06-29 8:24 ` [PATCH v7 1/3] MTD : add the common code for GPMI-NFC controller driver Huang Shijie
2011-06-29 8:24 ` Huang Shijie
2011-06-29 10:06 ` Wolfram Sang
2011-06-29 10:06 ` Wolfram Sang
2011-06-29 10:33 ` Wolfram Sang
2011-06-29 10:33 ` Wolfram Sang
2011-06-29 10:46 ` Huang Shijie
2011-06-29 10:46 ` Huang Shijie
2011-06-29 12:29 ` Wolfram Sang
2011-06-29 12:29 ` Wolfram Sang
2011-06-29 12:42 ` Russell King - ARM Linux
2011-06-29 12:42 ` Russell King - ARM Linux
2011-06-29 12:49 ` Wolfram Sang [this message]
2011-06-29 12:49 ` Wolfram Sang
2011-06-29 14:00 ` Shawn Guo
2011-06-29 14:00 ` Shawn Guo
2011-06-29 14:15 ` Wolfram Sang
2011-06-29 14:15 ` Wolfram Sang
2011-06-29 14:37 ` Shawn Guo
2011-06-29 14:37 ` Shawn Guo
2011-06-30 4:46 ` Wolfram Sang
2011-06-30 4:46 ` Wolfram Sang
2011-06-30 5:28 ` Shawn Guo
2011-06-30 5:28 ` Shawn Guo
2011-06-30 8:06 ` [PATCH] dmaengine: mxs-dma: skip request_irq for NO_IRQ Shawn Guo
2011-06-30 8:06 ` Shawn Guo
2011-07-07 0:15 ` Shawn Guo
2011-07-07 0:15 ` Shawn Guo
2011-07-07 2:06 ` Vinod Koul
2011-07-07 2:06 ` Vinod Koul
2011-07-07 3:24 ` Shawn Guo
2011-07-07 3:24 ` Shawn Guo
2011-07-07 3:23 ` Huang Shijie
2011-07-07 3:23 ` Huang Shijie
2011-07-13 23:31 ` Koul, Vinod
2011-07-13 23:31 ` Koul, Vinod
2011-06-29 12:38 ` [PATCH v7 1/3] MTD : add the common code for GPMI-NFC controller driver Russell King - ARM Linux
2011-06-29 12:38 ` Russell King - ARM Linux
2011-06-30 1:50 ` Huang Shijie
2011-06-30 1:50 ` Huang Shijie
2011-06-30 10:27 ` Wolfram Sang
2011-06-30 10:27 ` Wolfram Sang
2011-06-30 17:04 ` Wolfram Sang
2011-06-30 17:04 ` Wolfram Sang
2011-07-01 5:41 ` Artem Bityutskiy
2011-07-01 5:41 ` Artem Bityutskiy
2011-07-01 6:47 ` Huang Shijie
2011-07-01 6:47 ` Huang Shijie
2011-06-29 8:24 ` [PATCH v7 2/3] MTD : add support for imx23 and imx28 Huang Shijie
2011-06-29 8:24 ` Huang Shijie
2011-06-29 8:24 ` [PATCH v7 3/3] MTD : add GPMI-NFC driver in the config and Makefile Huang Shijie
2011-06-29 8:24 ` Huang Shijie
2011-06-30 10:40 ` [PATCH v7 0/3] add the GPMI controller driver for IMX23/IMX28 Wolfram Sang
2011-06-30 10:40 ` Wolfram Sang
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