• Brad Love's avatar
    media: em28xx: USB bulk packet size fix · c7c7e8d7
    Brad Love authored
    Hauppauge em28xx bulk devices exhibit continuity errors and corrupted
    packets, when run in VMWare virtual machines. Unknown if other
    manufacturers bulk models exhibit the same issue. KVM/Qemu is unaffected.
    
    According to documentation the maximum packet multiplier for em28xx in bulk
    transfer mode is 256 * 188 bytes. This changes the size of bulk transfers
    to maximum supported value and have a bonus beneficial alignment.
    
    Before:
    
    After:
    
    This sets up USB to expect just as many bytes as the em28xx is set to emit.
    
    Successful usage under load afterwards natively and in both VMWare
    and KVM/Qemu virtual machines.
    Signed-off-by: default avatarBrad Love <brad@nextdimension.cc>
    Reviewed-by: default avatarMichael Ira Krufky <mkrufky@linuxtv.org>
    Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
    c7c7e8d7
em28xx.h 23.4 KB