>It became apparent to me that there is a problem here. The size of dma_buf is >4096 bytes and maximum message length is 4096 too, we have pushed 12 bytes >packet_header to the buffer >and now there are 4084 bytes left for the message >in the buffer. Hence transfer of 4KB will cause buffer overflow and either >crash kernel or corrupt memory. One solution is to just always >push >packet_header using PIO, other to reduce max_write_len or increase dma_buf >size.
Yes, This is known to me and I will add separate patch for this to update quirks to take care for t186 and t194 to exclude packet hdr lengths There was separate patch when quirks were added and it got merged already from 5.0-rc1 but don’t want to sneak that here. Will send separate patch to take care of this. Need to update quirk to exclude packet header