diff options
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/cdns3/cdns3-gadget.c | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c index 4c6893af22dd..aeca902ab6cc 100644 --- a/drivers/usb/cdns3/cdns3-gadget.c +++ b/drivers/usb/cdns3/cdns3-gadget.c @@ -1120,6 +1120,7 @@ static int cdns3_ep_run_transfer(struct cdns3_endpoint *priv_ep, u32 togle_pcs = 1; int sg_iter = 0; int num_trb_req; + int trb_burst; int num_trb; int address; u32 control; @@ -1243,7 +1244,36 @@ static int cdns3_ep_run_transfer(struct cdns3_endpoint *priv_ep, total_tdl += DIV_ROUND_UP(length, priv_ep->endpoint.maxpacket); - trb->length |= cpu_to_le32(TRB_BURST_LEN(priv_ep->trb_burst_size) | + trb_burst = priv_ep->trb_burst_size; + + /* + * Supposed DMA cross 4k bounder problem should be fixed at DEV_VER_V2, but still + * met problem when do ISO transfer if sg enabled. + * + * Data pattern likes below when sg enabled, package size is 1k and mult is 2 + * [UVC Header(8B) ] [data(3k - 8)] ... + * + * The received data at offset 0xd000 will get 0xc000 data, len 0x70. Error happen + * as below pattern: + * 0xd000: wrong + * 0xe000: wrong + * 0xf000: correct + * 0x10000: wrong + * 0x11000: wrong + * 0x12000: correct + * ... + * + * But it is still unclear about why error have not happen below 0xd000, it should + * cross 4k bounder. But anyway, the below code can fix this problem. + * + * To avoid DMA cross 4k bounder at ISO transfer, reduce burst len according to 16. + */ + if (priv_ep->type == USB_ENDPOINT_XFER_ISOC && priv_dev->dev_ver <= DEV_VER_V2) + if (ALIGN_DOWN(trb->buffer, SZ_4K) != + ALIGN_DOWN(trb->buffer + length, SZ_4K)) + trb_burst = 16; + + trb->length |= cpu_to_le32(TRB_BURST_LEN(trb_burst) | TRB_LEN(length)); pcs = priv_ep->pcs ? TRB_CYCLE : 0; |