From cf77b5fb9b39445947e8027872c63cc16fb480fb Mon Sep 17 00:00:00 2001 From: Vahram Aharonyan Date: Wed, 9 Nov 2016 19:28:01 -0800 Subject: [PATCH] usb: dwc2: gadget: Transfer length limit checking for DDMA Add dwc2_gadget_get_chain_limit() function and its call in transfer start routine to correctly estimate one go on transfer size if descriptor DMA mode is selected. Signed-off-by: Vahram Aharonyan Signed-off-by: John Youn Signed-off-by: Felipe Balbi --- drivers/usb/dwc2/gadget.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index 729bc02d0f6e..4c1098f84431 100644 --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -601,6 +601,32 @@ static u32 dwc2_hsotg_read_frameno(struct dwc2_hsotg *hsotg) return dsts; } +/** + * dwc2_gadget_get_chain_limit - get the maximum data payload value of the + * DMA descriptor chain prepared for specific endpoint + * @hs_ep: The endpoint + * + * Return the maximum data that can be queued in one go on a given endpoint + * depending on its descriptor chain capacity so that transfers that + * are too long can be split. + */ +static unsigned int dwc2_gadget_get_chain_limit(struct dwc2_hsotg_ep *hs_ep) +{ + int is_isoc = hs_ep->isochronous; + unsigned int maxsize; + + if (is_isoc) + maxsize = hs_ep->dir_in ? DEV_DMA_ISOC_TX_NBYTES_LIMIT : + DEV_DMA_ISOC_RX_NBYTES_LIMIT; + else + maxsize = DEV_DMA_NBYTES_LIMIT; + + /* Above size of one descriptor was chosen, multiple it */ + maxsize *= MAX_DMA_DESC_NUM_GENERIC; + + return maxsize; +} + /** * dwc2_hsotg_start_req - start a USB request from an endpoint's queue * @hsotg: The controller state. @@ -659,7 +685,11 @@ static void dwc2_hsotg_start_req(struct dwc2_hsotg *hsotg, dev_dbg(hsotg->dev, "ureq->length:%d ureq->actual:%d\n", ureq->length, ureq->actual); - maxreq = get_ep_limit(hs_ep); + if (!using_desc_dma(hsotg)) + maxreq = get_ep_limit(hs_ep); + else + maxreq = dwc2_gadget_get_chain_limit(hs_ep); + if (length > maxreq) { int round = maxreq % hs_ep->ep.maxpacket;