From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH 2/5] ide: kill ide_toggle_bounce Date: Thu, 26 Apr 2018 09:11:21 -0600 Message-ID: <682db9af-33bc-639d-8930-7a66c30bc644@kernel.dk> References: <20180424181625.22410-1-hch@lst.de> <20180424181625.22410-3-hch@lst.de> <5aaca0d3-417f-57f3-969f-b4c777c3fd48@kernel.dk> <20180426072033.GA14700@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180426072033.GA14700-jcswGhMUV9g@public.gmane.org> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Christoph Hellwig Cc: linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-ide-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, "David S. Miller" List-Id: iommu@lists.linux-foundation.org On 4/26/18 1:20 AM, Christoph Hellwig wrote: > On Tue, Apr 24, 2018 at 08:02:56PM -0600, Jens Axboe wrote: >> On 4/24/18 12:16 PM, Christoph Hellwig wrote: >>> ide_toggle_bounce did select various strange block bounce limits, including >>> not bouncing at all as soon as an iommu is present in the system. Given >>> that the dma_map routines now handle any required bounce buffering except >>> for ISA DMA, and the ide code already must handle either ISA DMA or highmem >>> at least for iommu equipped systems we can get rid of the block layer >>> bounce limit setting entirely. >> >> Pretty sure I was the one to add this code, when highmem page IO was >> enabled about two decades ago... >> >> Outside of DMA, the issue was that the PIO code could not handle >> highmem. That's not the case anymore, so this should be fine. > > Yes, that is the rationale. Any chance to you could look over the > other patches as well? Except for the networking one for which I'd > really like to see a review from Dave all the users of the interface > are block related. You can add my reviewed-by to 1-3, and 5. Looks good to me. -- Jens Axboe