From: simon.kagstrom@netinsight.net (Simon =?UTF-8?B?S8OlZ3N0csO2bQ==?=) Date: Thu, 20 Mar 2014 12:05:00 +0100 Subject: [PATCH RESEND v2 1/2] ARM: ixp4xx: Make dma_set_coherent_mask common, correct implementation In-Reply-To: <201403201202.37065.arnd@arndb.de> References: <20140317144016.0508cc4d@marrow.netinsight.se> <20140320090330.49a1d372@marrow.netinsight.se> <201403201202.37065.arnd@arndb.de> Message-ID: <20140320120500.77948552@marrow.netinsight.se> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 20 Mar 2014 12:02:36 +0100 Arnd Bergmann wrote: > On Thursday 20 March 2014, Krzysztof Ha?asa wrote: > > Simon K?gstr?m writes: > > > > > Thanks. However, Krzysztof thinks that this implementation is > > > incorrect. It certainly fixes my ixp4xx issues, but might not be good > > > for everyone. > > > > It because you don't have PCI devices setting coherent mask to 32-bits > > (and that's what normal PCI devices do). > > > > BTW PCI (and other) devices requesting 32-bit coherent allocs don't care > > if they're given 26-bit memory. 26 bits fit perfectly in 32 bits. It's > > the streaming mapping which is (may be) constrained by hardware. > > Should I revert the patch then until we have a better fix? Yes, I think that would be good. Thanks to all for looking into it! // Simon