4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 244add8ebfb231c39db9e33b204bd0ce8f24f782 ]
In stream mode, when fast-forwarding TRBs, the stream number is not cleared causing the new stream to not get assigned. So we don't want controller to carry on transfers when short packet is received. So disable the CSP for stream capable endpoint.
This is based on the 3.30a Programming guide, where table 3-1 device descriptor structure field definitions says for CSP bit If this bit is 0, the controller generates an XferComplete event and remove the stream. So if we keep CSP as 1 then switching between streams would not happen as in stream mode, when fast-forwarding TRBs, the stream number is not cleared causing the new stream to not get assigned.
Signed-off-by: Tejas Joglekar joglekar@synopsys.com Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/dwc3/gadget.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 88f69d823be5..357a2b330137 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -990,9 +990,13 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb, usb_endpoint_type(dep->endpoint.desc)); }
- /* always enable Continue on Short Packet */ + /* + * Enable Continue on Short Packet + * when endpoint is not a stream capable + */ if (usb_endpoint_dir_out(dep->endpoint.desc)) { - trb->ctrl |= DWC3_TRB_CTRL_CSP; + if (!dep->stream_capable) + trb->ctrl |= DWC3_TRB_CTRL_CSP;
if (short_not_ok) trb->ctrl |= DWC3_TRB_CTRL_ISP_IMI;