[PATCH 4.19 03/95] usb: dwc2: gadget: Fix ISOC transfer complete handling for DDMA

From: Greg Kroah-Hartman
Date: Mon Oct 04 2021 - 09:08:17 EST


From: Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx>

commit dbe2518b2d8eabffa74dbf7d9fdd7dacddab7fc0 upstream.

When last descriptor in a descriptor list completed with XferComplete
interrupt, core switching to handle next descriptor and assert BNA
interrupt. Both these interrupts are set while dwc2_hsotg_epint()
handler called. Each interrupt should be handled separately: first
XferComplete interrupt then BNA interrupt, otherwise last completed
transfer will not be giveback to function driver as completed
request.

Fixes: 729cac693eec ("usb: dwc2: Change ISOC DDMA flow")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/a36981accc26cd674c5d8f8da6164344b94ec1fe.1631386531.git.Minas.Harutyunyan@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/dwc2/gadget.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -2919,9 +2919,7 @@ static void dwc2_hsotg_epint(struct dwc2

/* In DDMA handle isochronous requests separately */
if (using_desc_dma(hsotg) && hs_ep->isochronous) {
- /* XferCompl set along with BNA */
- if (!(ints & DXEPINT_BNAINTR))
- dwc2_gadget_complete_isoc_request_ddma(hs_ep);
+ dwc2_gadget_complete_isoc_request_ddma(hs_ep);
} else if (dir_in) {
/*
* We get OutDone from the FIFO, so we only