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* [PATCH v2] usb: cdnsp: fix issue with ZLP - added TD_SIZE = 1
@ 2022-10-24 14:04 Pawel Laszczak
  2022-10-27  7:24 ` Peter Chen
  0 siblings, 1 reply; 9+ messages in thread
From: Pawel Laszczak @ 2022-10-24 14:04 UTC (permalink / raw)
  To: peter.chen; +Cc: gregkh, linux-usb, linux-kernel, Pawel Laszczak, stable

Patch modifies the TD_SIZE in TRB before ZLP TRB.
The TD_SIZE in TRB before ZLP TRB must be set to 1 to force
processing ZLP TRB by controller.

cc: <stable@vger.kernel.org>
Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
Signed-off-by: Pawel Laszczak <pawell@cadence.com>

---
Changelog:
v2:
- returned value for last TRB must be 0

 drivers/usb/cdns3/cdnsp-ring.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/cdns3/cdnsp-ring.c b/drivers/usb/cdns3/cdnsp-ring.c
index 04dfcaa08dc4..aa79bce89d8a 100644
--- a/drivers/usb/cdns3/cdnsp-ring.c
+++ b/drivers/usb/cdns3/cdnsp-ring.c
@@ -1769,8 +1769,13 @@ static u32 cdnsp_td_remainder(struct cdnsp_device *pdev,
 
 	/* One TRB with a zero-length data packet. */
 	if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) ||
-	    trb_buff_len == td_total_len)
+	    trb_buff_len == td_total_len) {
+		/* Before ZLP driver needs set TD_SIZE=1. */
+		if (more_trbs_coming)
+			return 1;
+
 		return 0;
+	}
 
 	maxp = usb_endpoint_maxp(preq->pep->endpoint.desc);
 	total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2022-11-15  9:32 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-10-24 14:04 [PATCH v2] usb: cdnsp: fix issue with ZLP - added TD_SIZE = 1 Pawel Laszczak
2022-10-27  7:24 ` Peter Chen
2022-10-27  8:46   ` Pawel Laszczak
2022-11-06  9:02     ` Peter Chen
2022-11-07  5:39       ` Pawel Laszczak
2022-11-10  1:02         ` Peter Chen
2022-11-10  5:38           ` Pawel Laszczak
2022-11-11  1:28             ` Peter Chen
2022-11-15  9:31               ` Pawel Laszczak

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