From: Guennadi Liakhovetski <g.liakhovetski@gmx.de> To: Vinod Koul <vinod.koul@linux.intel.com> Cc: Magnus Damm <magnus.damm@gmail.com>, linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/7 v2] dma: sh: use an integer slave ID to improve API compatibility Date: Mon, 16 Jul 2012 06:37:28 +0000 [thread overview] Message-ID: <Pine.LNX.4.64.1207160832540.12302@axis700.grange> (raw) In-Reply-To: <1342418828.1726.37.camel@vkoul-udesk3> On Mon, 16 Jul 2012, Vinod Koul wrote: > On Thu, 2012-07-05 at 12:29 +0200, Guennadi Liakhovetski wrote: > > diff --git a/include/linux/sh_dma.h b/include/linux/sh_dma.h > > index a79f10a..4e83f3e 100644 > > --- a/include/linux/sh_dma.h > > +++ b/include/linux/sh_dma.h > > @@ -27,10 +27,10 @@ struct sh_dmae_slave { > > * a certain peripheral > > */ > > struct sh_dmae_slave_config { > > - unsigned int slave_id; > > - dma_addr_t addr; > > - u32 chcr; > > - char mid_rid; > > + int slave_id; > > + dma_addr_t addr; > > + u32 chcr; > > + char mid_rid; > > }; > why would you want to keep your own slave_id and addr fields when they > are already provided in struct dma_slave_config. Modifying the driver's API would break all its clients. > Also while at it, what > would be the use of last tow fields, what do they describe? They tell the driver how the channel has to be configured to support this specific client. They are values of two specific registers. In fact, CHCR means exactly that - CHannel Control Register. > Would it be possible to get rid of this structure completely? At least > first two fields should go away. Migration has to be performed gradually. If this approach and patches are accepted, then all client drivers can be migrated, then thr legacy API can be dropped. Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/
WARNING: multiple messages have this Message-ID (diff)
From: Guennadi Liakhovetski <g.liakhovetski@gmx.de> To: Vinod Koul <vinod.koul@linux.intel.com> Cc: Magnus Damm <magnus.damm@gmail.com>, linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/7 v2] dma: sh: use an integer slave ID to improve API compatibility Date: Mon, 16 Jul 2012 08:37:28 +0200 (CEST) [thread overview] Message-ID: <Pine.LNX.4.64.1207160832540.12302@axis700.grange> (raw) In-Reply-To: <1342418828.1726.37.camel@vkoul-udesk3> On Mon, 16 Jul 2012, Vinod Koul wrote: > On Thu, 2012-07-05 at 12:29 +0200, Guennadi Liakhovetski wrote: > > diff --git a/include/linux/sh_dma.h b/include/linux/sh_dma.h > > index a79f10a..4e83f3e 100644 > > --- a/include/linux/sh_dma.h > > +++ b/include/linux/sh_dma.h > > @@ -27,10 +27,10 @@ struct sh_dmae_slave { > > * a certain peripheral > > */ > > struct sh_dmae_slave_config { > > - unsigned int slave_id; > > - dma_addr_t addr; > > - u32 chcr; > > - char mid_rid; > > + int slave_id; > > + dma_addr_t addr; > > + u32 chcr; > > + char mid_rid; > > }; > why would you want to keep your own slave_id and addr fields when they > are already provided in struct dma_slave_config. Modifying the driver's API would break all its clients. > Also while at it, what > would be the use of last tow fields, what do they describe? They tell the driver how the channel has to be configured to support this specific client. They are values of two specific registers. In fact, CHCR means exactly that - CHannel Control Register. > Would it be possible to get rid of this structure completely? At least > first two fields should go away. Migration has to be performed gradually. If this approach and patches are accepted, then all client drivers can be migrated, then thr legacy API can be dropped. Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/
next prev parent reply other threads:[~2012-07-16 6:37 UTC|newest] Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-07-05 10:29 [PATCH 0/7 v2] dma: sh: stop using .private Guennadi Liakhovetski 2012-07-05 10:29 ` Guennadi Liakhovetski 2012-07-05 10:29 ` [PATCH 1/7 v2] dmaengine: shdma: (cosmetic) simplify a static function Guennadi Liakhovetski 2012-07-05 10:29 ` Guennadi Liakhovetski 2012-07-05 10:29 ` [PATCH 2/7 v2] ASoC: siu: don't use DMA device for channel filtering Guennadi Liakhovetski 2012-07-05 10:29 ` Guennadi Liakhovetski 2012-07-05 12:08 ` Mark Brown 2012-07-05 12:08 ` Mark Brown 2012-07-05 13:54 ` Guennadi Liakhovetski 2012-07-05 13:54 ` Guennadi Liakhovetski 2012-07-05 14:00 ` Mark Brown 2012-07-05 14:00 ` Mark Brown 2012-07-05 14:08 ` Guennadi Liakhovetski 2012-07-05 14:08 ` Guennadi Liakhovetski 2012-07-05 10:29 ` [PATCH 3/7 v2] sh: remove unused DMA device pointer from SIU platform data Guennadi Liakhovetski 2012-07-05 10:29 ` Guennadi Liakhovetski 2012-07-05 10:29 ` [PATCH 4/7 v2] dmaengine: shdma: prepare to stop using struct dma_chan::private Guennadi Liakhovetski 2012-07-05 10:29 ` Guennadi Liakhovetski 2012-07-05 10:29 ` [PATCH 5/7 v2] dma: sh: use an integer slave ID to improve API compatibility Guennadi Liakhovetski 2012-07-05 10:29 ` Guennadi Liakhovetski 2012-07-16 6:07 ` Vinod Koul 2012-07-16 6:19 ` Vinod Koul 2012-07-16 6:37 ` Guennadi Liakhovetski [this message] 2012-07-16 6:37 ` Guennadi Liakhovetski 2012-07-16 6:53 ` Vinod Koul 2012-07-16 6:57 ` Vinod Koul 2012-07-16 7:13 ` Guennadi Liakhovetski 2012-07-16 7:13 ` Guennadi Liakhovetski 2012-07-16 8:28 ` Vinod Koul 2012-07-16 8:40 ` Vinod Koul 2012-07-16 8:47 ` Guennadi Liakhovetski 2012-07-16 8:47 ` Guennadi Liakhovetski 2012-07-16 9:37 ` Vinod Koul 2012-07-16 9:49 ` Vinod Koul 2012-07-16 10:01 ` Guennadi Liakhovetski 2012-07-16 10:01 ` Guennadi Liakhovetski 2012-07-16 10:24 ` Vinod Koul 2012-07-16 10:36 ` Vinod Koul 2012-07-16 10:55 ` Guennadi Liakhovetski 2012-07-16 10:55 ` Guennadi Liakhovetski 2012-07-16 11:12 ` Vinod Koul 2012-07-16 11:24 ` Vinod Koul 2012-07-16 12:47 ` Guennadi Liakhovetski 2012-07-16 12:47 ` Guennadi Liakhovetski 2012-07-18 3:14 ` Vinod Koul 2012-07-18 3:26 ` Vinod Koul 2012-07-18 8:34 ` Guennadi Liakhovetski 2012-07-18 8:34 ` Guennadi Liakhovetski 2012-07-05 10:29 ` [PATCH 6/7 v2] dma: sh: provide a migration path for slave drivers to stop using .private Guennadi Liakhovetski 2012-07-05 10:29 ` Guennadi Liakhovetski 2012-07-16 6:19 ` Vinod Koul 2012-07-16 6:31 ` Vinod Koul 2012-07-16 6:31 ` Guennadi Liakhovetski 2012-07-16 6:31 ` Guennadi Liakhovetski 2012-07-05 10:29 ` [PATCH 7/7 v2] mmc: sh_mmcif: switch to the new DMA channel allocation and configuration Guennadi Liakhovetski 2012-07-05 10:29 ` Guennadi Liakhovetski 2012-07-20 6:00 ` [PATCH 0/7 v2] dma: sh: stop using .private Vinod Koul 2012-07-20 6:12 ` Vinod Koul
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