Files
linux/drivers/media
Brad Love e4504b80e0 media: em28xx: USB bulk packet size fix
[ Upstream commit c7c7e8d780 ]

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: Brad Love <brad@nextdimension.cc>
Reviewed-by: Michael Ira Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-25 16:17:42 +02:00
..
2018-02-25 11:07:55 +01:00
2018-03-24 11:01:22 +01:00