On 1.10.2021 10.22, Pavankumar Kondeti wrote: > The command ring pointer is located at [6:63] bits of the command > ring control register (CRCR). All the control bits like command stop, > abort are located at [0:3] bits. While aborting a command, we read the > CRCR and set the abort bit and write to the CRCR. The read will always > give command ring pointer as all zeros. So we essentially write only > the control bits. Since we split the 64 bit write into two 32 bit writes, > there is a possibility of xHC command ring stopped before the upper > dword (all zeros) is written. If that happens, xHC updates the upper > dword of its internal command ring pointer with all zeros. Next time, > when the command ring is restarted, we see xHC memory access failures. > Fix this issue by only writing to the lower dword of CRCR where all > control bits are located. > > Signed-off-by: Pavankumar Kondeti <pkondeti@xxxxxxxxxxxxxx> Thanks, nice catch. Adding to queue -Mathias
