On 4/11/2017 12:36 AM, Felipe Balbi wrote:
Hi,
Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> writes:
Felipe Balbi <balbi@xxxxxxxxxx> writes:
Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> writes:
This patch fixes a commit that causes a hang from device waiting for
data with the wrong sequence number. The commit ffb80fc672c3 ("usb:
dwc3: gadget: skip Set/Clear Halt when invalid") adds a check to return
early depending on DWC3_EP_STALL is set or not, prevent sending the ep
halt command to HW endpoint to do CLEAR_FEATURE(ENDPOINT_HALT) request.
This was to workaround the issue for macOS where the device hangs from
sending DWC3 clear stall command.
In USB 3.1 spec, 9.4.5, CLEAR_FEATURE(ENDPOINT_HALT) request always
results in the data sequence being reinitialized to zero regardless
whether the endpoint has been halted or not. Some device class depends
on this feature for its protocol. For instance, in mass storage class,
there is MSC reset protocol that does CLEAR_FEATURE(ENDPOINT_HALT) on
bulk endpoints. This protocol reinitializes the data sequence and
ensures that whatever pending data requested from previous CBW will be
reset. Otherwise this will cause a hang as the device can wait for the
data with the wrong sequence number from the previous CBW. We found this
failure in USB CV: MSC Error Recovery Test with f_mass_storage.
This patch fixes this issue by checking to see whether the set/halt ep
call is a protocol call before early exit to make sure that set/clear
halt endpoint command can go through if it is a device class protocol.
Fixes: ffb80fc672c3 ("usb: dwc3: gadget: skip Set/Clear Halt when invalid")
Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
this will regress the macOS case I wrote that commit for. We need to
no wait, it won't regress macOS, but we're still left with the problem
of host and peripheral being able to get DataToggle/SeqN out of sync.
This patch is for the regression we have. Can you provide more
information for the macOS? I'm not sure if this is the case for macOS,
I need to find a way to reproduce it again first. When I first
reproduced it was with dwc3 running adb and connecting it to a macOS
machine.
but maybe there is still pending transfer when it tries to send the
request? (There shouldn't be any before issuing ClearStall command). Do
this could be, I don't remember if I checked this or not :-)
Really, the best way here, IMHO, would be to re-verify what's going on
with macOS and revert my orignal patch since it's, rather clearly,
wrong.
Sure. Are you going to make a revert patch or I am?
Thanks,
Thinh