The function cdns3_ep_config() calculates the maximum packet size based
on the Endpoint Type and the Gadget Speed and stores it in the variable
"max_packet_size". This value is then programmed in the USB Controller
for the corresponding Endpoint. This may result in a mismatch between
the maximum packet size programmed in the USB controller and the maximum
packet size seen by the UDC Core via "maxpacket" member of "struct usb_ep".
Additionally, since TD_SIZE as well as TOTAL_TDL are calculated in
cdns3_ep_run_transfer() on the basis of the maximum packet size stored in
the "maxpacket" member of "struct usb_ep", it may lead to incorrect values
of TD_SIZE and TOTAL_TDL when compared with what the USB controller
actually expects (max_packet_size). This also applies to the calculation of
TDL in cdns3_ep_run_stream_transfer().
Fix this.
Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Signed-off-by: Siddharth Vadapalli <s-vadapalli@xxxxxx>
---
Hello,
This patch is based on commit
1d227fcc7222 Merge tag 'net-6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
of Mainline Linux.
Regards,
Siddharth.
drivers/usb/cdns3/cdns3-gadget.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index fd1beb10bba7..e89bd248e81d 100644
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -2145,6 +2145,16 @@ int cdns3_ep_config(struct cdns3_endpoint *priv_ep, bool enable)
return -EINVAL;
}
+ /*
+ * The Endpoint is configured to handle a maximum packet size of
+ * max_packet_size. Hence, set priv_ep->endpoint.maxpacket to
+ * max_packet_size. This is necessary to ensure that TD_SIZE and
+ * TOTAL_TDL are calculated correctly in cdns3_ep_run_transfer(),
+ * and also to ensure that TDL is calculated correctly in
+ * cdns3_ep_run_stream_transfer().
+ */
+ priv_ep->endpoint.maxpacket = max_packet_size;
+
if (max_packet_size == 1024)
priv_ep->trb_burst_size = 128;
else if (max_packet_size >= 512)
--
2.40.1
