On 22-10-19 02:07:17, Pawel Laszczak wrote:
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
drivers/usb/cdns3/cdnsp-ring.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/cdns3/cdnsp-ring.c b/drivers/usb/cdns3/cdnsp-ring.c index 794e413800ae..4809d0e894bb 100644 --- a/drivers/usb/cdns3/cdnsp-ring.c +++ b/drivers/usb/cdns3/cdnsp-ring.c @@ -1765,18 +1765,19 @@ static u32 cdnsp_td_remainder(struct
cdnsp_device *pdev,
struct cdnsp_request *preq, bool more_trbs_coming){
- u32 maxp, total_packet_count;
- /* One TRB with a zero-length data packet. */
- if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) ||
trb_buff_len == td_total_len)return 0;
u32 maxp, total_packet_count, remainder;
maxp = usb_endpoint_maxp(preq->pep->endpoint.desc); total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
/* Queuing functions don't count the current TRB into transferred. */
- return (total_packet_count - ((transferred + trb_buff_len) / maxp));
- remainder = (total_packet_count - ((transferred + trb_buff_len) /
+maxp));
- /* Before ZLP driver needs set TD_SIZE=1. */
- if (!remainder && more_trbs_coming)
remainder = 1;Without ZLP, TD_SIZE = 0 for the last TRB. With ZLP, TD_SIZE = 1 for current TRB, and TD_SIZE = 0 for the next TRB (the last zero-length packet) right?
Yes, you have right.
Pawel, With your changes, the return value is 1 for function cdnsp_queue_ctrl_tx. Without your changes, it is 0, something wrong?
Yes you have right. It does not cause a problem, but it's not according with controller specification.
I posted the fixed version of this patch.
Thanks, Pawel