diff options
| -rw-r--r-- | drivers/usb/dwc2/gadget.c | 37 |
1 files changed, 27 insertions, 10 deletions
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index 43947673696d..b3976876c06b 100644 --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -2298,6 +2298,7 @@ static void dwc2_hsotg_rx_data(struct dwc2_hsotg *hsotg, int ep_idx, int size) int to_read; int max_req; int read_ptr; + u32 drain; if (!hs_req) { u32 epctl = dwc2_readl(hsotg, DOEPCTL(ep_idx)); @@ -2317,30 +2318,46 @@ static void dwc2_hsotg_rx_data(struct dwc2_hsotg *hsotg, int ep_idx, int size) to_read = size; read_ptr = hs_req->req.actual; max_req = hs_req->req.length - read_ptr; + drain = 0; dev_dbg(hsotg->dev, "%s: read %d/%d, done %d/%d\n", __func__, to_read, max_req, read_ptr, hs_req->req.length); if (to_read > max_req) { /* - * more data appeared than we where willing - * to deal with in this request. + * More data appeared than we were willing to deal with in + * this request. Keep only what fits in the request buffer + * and discard the rest from the FIFO, instead of overwriting + * bytes past the request buffer (a 64-byte packet into a + * request with one byte left used to over-write 63 bytes past + * its end). */ - - /* currently we don't deal this */ - WARN_ON_ONCE(1); + dev_dbg(hsotg->dev, "%s: packet %d > request space %d, dropping %d\n", + __func__, to_read, max_req, to_read - max_req); + drain = DIV_ROUND_UP(to_read - max_req, 4); + to_read = max_req; } hs_ep->total_data += to_read; hs_req->req.actual += to_read; - to_read = DIV_ROUND_UP(to_read, 4); /* - * note, we might over-write the buffer end by 3 bytes depending on - * alignment of the data. + * Copy word-at-a-time so the request buffer is exactly filled and + * never over-run by the 4-byte rounding of the previous FIFO bulk + * read (which could also emit up to 3 bytes past the buffer end). */ - dwc2_readl_rep(hsotg, EPFIFO(ep_idx), - hs_req->req.buf + read_ptr, to_read); + while (to_read > 0) { + u32 word = dwc2_readl(hsotg, EPFIFO(ep_idx)); + unsigned int chunk = min_t(unsigned int, to_read, 4); + + memcpy(hs_req->req.buf + read_ptr, &word, chunk); + read_ptr += chunk; + to_read -= chunk; + } + + /* drain the discarded bytes so the next FIFO event is a fresh packet */ + while (drain-- > 0) + (void)dwc2_readl(hsotg, EPFIFO(ep_idx)); } /** |