diff options
| author | Brad Love <brad@nextdimension.cc> | 2018-01-04 19:04:13 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-30 07:49:14 +0200 |
| commit | b2895b916282b09d42ec789dfd234091c788a5ad (patch) | |
| tree | b336b83cf1a261cdbbe6e8343e4f25d385779958 | |
| parent | 1f8b926275550719fb9f9541df1b039d8caa9e33 (diff) | |
media: em28xx: USB bulk packet size fix
[ Upstream commit c7c7e8d7803406daa21e96d00c357de8b77b6764 ]
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>
| -rw-r--r-- | drivers/media/usb/em28xx/em28xx.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/media/usb/em28xx/em28xx.h b/drivers/media/usb/em28xx/em28xx.h index 76bf8ba372b3..5b53e31ce262 100644 --- a/drivers/media/usb/em28xx/em28xx.h +++ b/drivers/media/usb/em28xx/em28xx.h @@ -187,7 +187,7 @@ USB 2.0 spec says bulk packet size is always 512 bytes */ #define EM28XX_BULK_PACKET_MULTIPLIER 384 -#define EM28XX_DVB_BULK_PACKET_MULTIPLIER 384 +#define EM28XX_DVB_BULK_PACKET_MULTIPLIER 94 #define EM28XX_INTERLACED_DEFAULT 1 |