From mboxrd@z Thu Jan 1 00:00:00 1970 From: vinod.koul@intel.com (Vinod Koul) Date: Fri, 9 Dec 2016 23:23:49 +0530 Subject: Tearing down DMA transfer setup after DMA client has finished In-Reply-To: References: <20161207164341.GX6408@localhost> <20161208103921.GC6408@localhost> <91b0d10c-1bc2-c3e1-4088-f4ad9adcd6c0@free.fr> <20161208163755.GH6408@localhost> <20161209065955.GJ6408@localhost> <6ce1ea97-1d68-2203-c7b4-73315e801655@laposte.net> <20161209171727.GK6408@localhost> Message-ID: <20161209175349.GL6408@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Dec 09, 2016 at 05:28:01PM +0000, M?ns Rullg?rd wrote: > Vinod Koul writes: > > > On Fri, Dec 09, 2016 at 11:25:57AM +0100, Sebastian Frias wrote: > >> > >> What concrete solution do you propose? > > > > I have already proposed two solutions. > > > > A) Request a channel only when you need it. Obviously we can't do virtual > > channels with this (though we should still use virt-channels framework). > > The sbox setup and teardown can be done as part of channel request and > > freeup. PL08x already does this. > > > > Downside is that we can only have as many consumers at a time as channels. > > > > I have not heard any technical reason for not doing this apart from drivers > > grab the channel at probe, which is incorrect and needs to be fixed > > irrespective of the problem at hand. > > > > This is my preferred option. > > Sorry, but this is not acceptable. without outlining why.. > > > B) Create a custom driver specific API. This API for example: > > sbox_setup(bool enable, ...) > > can be called by client to explicitly setup and clear up the sbox setting. > > > > This way we can have transactions muxed. > > > > I have not heard any arguments on why we shouldn't do this except Russell's > > comment that A) solves this. > > Driver-specific interfaces are not the solution. That way lies chaos > and madness. Yes fair enough. So would API change which 99% world doesnt need. > This would all be so much easier if you all would just shut up for a > moment and let me fix it properly. Oh please go away, noone is asking you to reply! -- ~Vinod