From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Tue, 06 Aug 2019 05:29:49 +0000 Subject: Re: [PATCH 4/7] ALSA: pcm: use dma_can_mmap() to check if a device supports dma_mmap_* Message-Id: <20190806052949.GC13409@lst.de> List-Id: References: <20190805091159.7826-5-hch@lst.de> In-Reply-To: <20190805091159.7826-5-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sh@vger.kernel.org On Mon, Aug 05, 2019 at 11:22:03AM +0200, Takashi Iwai wrote: > This won't work as expected, unfortunately. It's a bit tricky check, > since the driver may have its own mmap implementation via > substream->ops->mmap, and the dma_buffer.dev.dev might point to > another object depending on the dma_buffer.dev.type. > > So please replace with something like below: >From my gut feeling I'd reorder it a bit to make it more clear like this: http://git.infradead.org/users/hch/misc.git/commitdiff/958fccf54d00c16740522f818d23f9350498e911 if this is fine it'll be in the next version, waiting for a little more feedback on the other patches.