On Thu, Nov 10, 2022 at 07:31:34PM +0200, Yaron Micher wrote: > The rx descriptor list is in cached memory, and there may be multiple > descriptors per cache-line. After reclaim_rx_buffers marks a descriptor > as unused it does a cache flush, which causes the entire cache-line to > be written to memory, which may override other descriptors in the same > cache-line that the controller may have written to. > > The fix skips freeing descriptors that are not the last in a cache-line, > and if the freed descriptor is the last one in a cache-line, it marks > all the descriptors in the cache-line as unused. > This is similarly to what is done in drivers/net/fec_mxc.c > > In my case this bug caused tftpboot to fail some times when other > packets are sent to u-boot in addition to the ongoing tftp (e.g. ping). > The driver would stop receiving new packets because it is waiting > on a descriptor that is marked unused, when in reality the descriptor > contains a new unprocessed packet but while freeing the previous buffer > descriptor & flushing the cache, the driver accidentally marked the > descriptor as unused. > > Signed-off-by: Yaron Micher <yar...@hailo.ai>
Applied to u-boot/master, thanks! -- Tom
signature.asc
Description: PGP signature
