From: Vahram Aharonyan <vahr...@synopsys.com>
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 <vahr...@synopsys.com>
Signed-off-by: John Youn <johny...@synopsys.com>
---
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 729bc02d..4c1098f 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.
@@ -658,8 +684,12 @@ static void dwc2_hsotg_start_req(struct dwc2_hsotg *hsotg,
length = ureq->length - ureq->actual;
dev_dbg(hsotg->dev, "ureq->length:%d ureq->actual:%d\n",
ureq->length, ureq->actual);
+
+ if (!using_desc_dma(hsotg))
+ maxreq = get_ep_limit(hs_ep);
+ else
+ maxreq = dwc2_gadget_get_chain_limit(hs_ep);
- maxreq = get_ep_limit(hs_ep);
if (length > maxreq) {
int round = maxreq % hs_ep->ep.maxpacket;
--
2.10.0
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