[+cc ARM64 folks, linux-kernel] The original patch under discussion is: https://lkml.kernel.org/r/20180521220514.30256-1-marek.vasut+renesas@xxxxxxxxx On Tue, May 22, 2018 at 11:52:21AM +0200, Marek Vasut wrote: > On 05/22/2018 10:10 AM, Arnd Bergmann wrote: > > On Tue, May 22, 2018 at 12:05 AM, Marek Vasut <marek.vasut@xxxxxxxxx> wrote: > >> From: Phil Edworthy <phil.edworthy@xxxxxxxxxxx> > >> > >> The PCIe DMA controller on RCar Gen2 and earlier is on 32bit bus, > >> so limit the DMA range to 32bit. > >> > >> Signed-off-by: Phil Edworthy <phil.edworthy@xxxxxxxxxxx> > >> Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxx> > >> Cc: Arnd Bergmann <arnd@xxxxxxxx> > >> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> > >> Cc: Phil Edworthy <phil.edworthy@xxxxxxxxxxx> > >> Cc: Simon Horman <horms+renesas@xxxxxxxxxxxx> > >> Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx> > >> Cc: linux-renesas-soc@xxxxxxxxxxxxxxx > >> To: linux-pci@xxxxxxxxxxxxxxx > >> --- > >> NOTE: I'm aware of https://patchwork.kernel.org/patch/9495895/ , but the > >> discussion seems to have gone way off, so I'm sending this as a > >> RFC. Any feedback on how to do this limiting properly would be nice. > > > > Doing it in the driver is clearly not appropriate, we must do this in > > common code. If I remember correctly, it's specifically ARM64 that is > > broken here, it incorrectly allows setting a DMA mask to 64 bit > > when that is not available. > > Yep, that's correct. ARM64 with devices mapping tremendous amounts of > memory. So did anything change since that discussion references in the NOTE? > > -- > Best regards, > Marek Vasut
