From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guo Ren Subject: Re: [PATCH V7 1/2] csky/dma: bugfix dma_sync_for_cpu/device Date: Tue, 25 Sep 2018 17:46:03 +0800 Message-ID: <20180925094601.GA2102@guoren> References: <1ccf1bed89758a5a9b57ac2ce6d11ca898a1b9ae.1537276837.git.ren_guo@c-sky.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Arnd Bergmann Cc: Thomas Gleixner , Jason Cooper , Marc Zyngier , Rob Herring , Mark Rutland , Rob Herring , Stephen Rothwell , Linux Kernel Mailing List , DTML , linux-arch , c-sky_gcc_upstream@c-sky.com, gnu-csky@mentor.com, Greentime Hu List-Id: devicetree@vger.kernel.org On Mon, Sep 24, 2018 at 10:38:04PM +0200, Arnd Bergmann wrote: > On Tue, Sep 18, 2018 at 3:48 PM Guo Ren wrote: > > > > ref: https://lkml.org/lkml/2018/5/18/1068 > > > > map for_cpu for_device unmap > > TO_DEV writeback none writeback none > > TO_CPU invalidate invalidate* invalidate invalidate* > > BIDIR writeback invalidate writeback invalidate > > > > Signed-off-by: Guo Ren > > Same comment as for the other patch: Explain why the original > version is wrong first. When giving a reference to some other > discussion, use the "Link" tag above your Signed-off-by line. > To point to a discussion on lkml, lore.kernel.org is the > recommended archive, so it would become > > Link: https://lore.kernel.org/lkml/20180518215548.GH17671@n2100.armlinux.org.uk/ Ok, I'll improve the comment: Fixup dma_mapping error in linux-4.19-rc3, and we must implement all DMA_TO_DEVICE/FROM_DEVICE/BIDIRECTIONAL for both sync_dma_for_device/cpu. The implementation of arch should follow the following rules: map for_cpu for_device unmap TO_DEV writeback none writeback none TO_CPU invalidate invalidate* invalidate invalidate* BIDIR writeback invalidate writeback invalidate Link: https://lore.kernel.org/lkml/20180518215548.GH17671@n2100.armlinux.org.uk/ Signed-off-by: Guo Ren Best Regards Guo Ren