linux-kernel - Re: [PATCH] serial: sh-sci: don't filter on DMA device, use only channel ID

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20110908012119.GJ22142@linux-sh.org>
Date:	Thu, 8 Sep 2011 10:21:20 +0900
From:	Paul Mundt <lethal@...ux-sh.org>
To:	"Koul, Vinod" <vinod.koul@...el.com>
Cc:	"g.liakhovetski@....de" <g.liakhovetski@....de>,
	"Williams, Dan J" <dan.j.williams@...el.com>,
	"magnus.damm@...il.com" <magnus.damm@...il.com>,
	"linux-sh@...r.kernel.org" <linux-sh@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"damm@...nsource.se" <damm@...nsource.se>
Subject: Re: [PATCH] serial: sh-sci: don't filter on DMA device, use only channel ID

On Thu, Sep 08, 2011 at 03:07:53AM +0530, Koul, Vinod wrote:
> On Wed, 2011-09-07 at 22:01 +0200, Guennadi Liakhovetski wrote:
> > On Thu, 8 Sep 2011, Koul, Vinod wrote:
> > You're seriously suggesting to export and use an additional shdma private 
> > function, bypassing the dmaengine API?... That really doesn't sound like a 
> > good idea to me, sorry. How about using .device_control(DMA_SLAVE_CONFIG) 
> > from the filter function directly to verify channel suitability?
> Yes see stedma40, coh90138 drivers
> .device_control is not right place as channel is already allocated.
> 

No, that's not going to happen either. Many of these drivers are used in
different CPUs with different DMACs. The dmaengine driver in question
only applies to a subset, so the driver bits need to be wholly generic.
In short, if the dmaengine API can't handle this sort of stuff then it's
the dmaengine API that needs to be extended, we won't be working around
dmaengine shortcomings in drivers that simply want a sensible DMA API to
plug in to.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/