Hi Scott, > -----Original Message----- > On Mon, 2018-08-27 at 20:15 +0200, Christian Zigotzky wrote: > > Hello, > > > > Our users tested the RC1 of kernel 4.19 on their P5020 boards today. > > Unfortunately the USB bug still exists. With mem values bigger than > 4096M, > > the USB mouse and keyboard doesn’t work. With the bootarg mem=4096M, the > USB > > devices work without any problems. Please compile the RC1 and test it on > > your P5020 board. There is a problem with the memory management since > > 22/08/18. > > I just tested 4.19-rc1 on a T4240 and got a similar problem with MMC. MMC > and > USB on these chips both have a 32-bit DMA limitation. I'll look into it.
I encountered similar issues on LS104xA chips. This is the workaround for MMC: https://patchwork.kernel.org/patch/10506627/ On the USB side I didn't find a proper place in the usb subsystem code for a workaround but instead found an undocumented kernel arg (*) that limits the dma mask to 32 bits: xhci-hcd.quirks=0x800000. (*) https://patchwork.kernel.org/patch/10509159/ --- Best Regards, Laurentiu
