On 1/3/20 10:17 AM, Al Cooper wrote:

When the EHCI controller received a 512 byte USB packet that
had to be broken into 2 256 byte bursts across the SCB bus AND
there was a following 512 byte USB packet, the second burst of
data from the first packet was sometimes being lost. If the
burst size was changed to 128 bytes via the EBR_SCB_SIZE field
in the USB_CTRL_EBRIDGE register we'd see the 4th 128 byte burst
of the first packet being lost. This problem became much worse
if other threads were running that accessed memory, like a memcpy
test. Setting the EBR_SCB_SIZE to 512, which prevents breaking
the EHCI USB packet (max size of 512 bytes) into bursts, fixed
the problem.

Signed-off-by: Al Cooper <alcooperx@gmail.com>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel