On Tue, Dec 20, 2016 at 05:34:34PM +0100, Ralf Baechle wrote: > On Fri, Dec 02, 2016 at 09:42:09AM -0600, Nathan Sullivan wrote: > > Date: Fri, 2 Dec 2016 09:42:09 -0600 > > From: Nathan Sullivan <nathan.sullivan@xxxxxx> > > To: ralf@xxxxxxxxxxxxxx, mark.rutland@xxxxxxx, robh+dt@xxxxxxxxxx > > CC: linux-mips@xxxxxxxxxxxxxx, devicetree@xxxxxxxxxxxxxxx, > > linux-kernel@xxxxxxxxxxxxxxx, Nathan Sullivan <nathan.sullivan@xxxxxx> > > Subject: [PATCH] MIPS: NI 169445 board support > > Content-Type: text/plain > > > > Support the National Instruments 169445 board. > > Nathan, > > I assume you're going to repost the changes Rob asked for in > https://patchwork.linux-mips.org/patch/14641/#26924 and resubmit? > > Thanks, > > Ralf Hmm, I found the issue with the generic MIPS config and dwc_eth_qos. The NIC driver attempts to cache align a descriptor ring using the ___cacheline_aligned attribute on the descriptor struct, in combination with a "skip" feature in hardware. However, the skip feature only has a three bit field, and the generic MIPS config selects MIPS_L1_CACHE_SHIFT_7. So, the line size is 128, and with a 64-bit bus, that means the NIC descriptor skip field would need to be set to 14 to align the 16-byte descriptors... I guess it makes sense for a generic MIPS kernel to align everything for 128 byte cache lines, and for me to fix the dwc_eth_qos driver to handle cases where the line size is too big for the hardware skip feature, right? Thanks, Nathan
