4.20-stable review patch. If anyone has any objections, please let me know.
------------------
From: Tejas Joglekar tejas.joglekar@synopsys.com
commit 1e19cdc8060227b0802bda6bc0bd22b23679ba32 upstream.
For OUT endpoints, zero-length transfers require MaxPacketSize buffer as per the DWC_usb3 programming guide 3.30a section 4.2.3.3.
This patch fixes this by explicitly checking zero length transfer to correctly pad up to MaxPacketSize.
Fixes: c6267a51639b ("usb: dwc3: gadget: align transfers to wMaxPacketSize") Cc: stable@vger.kernel.org
Signed-off-by: Tejas Joglekar joglekar@synopsys.com Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/dwc3/gadget.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1119,7 +1119,7 @@ static void dwc3_prepare_one_trb_linear( unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc); unsigned int rem = length % maxp;
- if (rem && usb_endpoint_dir_out(dep->endpoint.desc)) { + if ((!length || rem) && usb_endpoint_dir_out(dep->endpoint.desc)) { struct dwc3 *dwc = dep->dwc; struct dwc3_trb *trb;