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authorBrad Love <brad@nextdimension.cc>2018-01-04 19:04:13 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-05-30 07:49:14 +0200
commitb2895b916282b09d42ec789dfd234091c788a5ad (patch)
treeb336b83cf1a261cdbbe6e8343e4f25d385779958 /drivers/media
parent1f8b926275550719fb9f9541df1b039d8caa9e33 (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>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/usb/em28xx/em28xx.h2
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