[PATCH] usb: dwc3: Set the ClearPendIN bit on Clear Stall EP command

[John Youn <johnyoun@xxxxxxxxxxxx>]

As of core revision 2.60a the recommended programming model is to set
the ClearPendIN bit when issuing a Clear Stall EP command for IN
endpoints. This is to prevent an issue where some hosts may not send ACK
TPs for pending IN transfers due to various error conditions. Synopsys
STAR 9000614252.

Signed-off-by: John Youn <johnyoun@xxxxxxxxxxxx>
---
 drivers/usb/dwc3/core.h   |  1 +
 drivers/usb/dwc3/gadget.c | 23 +++++++++++++++++------
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 74dff47..dcdba14 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -417,6 +417,7 @@
 #define DWC3_DEPCMD_GET_RSC_IDX(x)	(((x) >> DWC3_DEPCMD_PARAM_SHIFT) & 0x7f)
 #define DWC3_DEPCMD_STATUS(x)		(((x) >> 12) & 0x0F)
 #define DWC3_DEPCMD_HIPRI_FORCERM	(1 << 11)
+#define DWC3_DEPCMD_CLEARPENDIN		(1 << 11)
 #define DWC3_DEPCMD_CMDACT		(1 << 10)
 #define DWC3_DEPCMD_CMDIOC		(1 << 8)
 
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 7732650..86d9edb 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -334,6 +334,21 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned cmd,
 	return ret;
 }
 
+static int dwc3_send_clear_stall_ep_cmd(struct dwc3_ep *dep)
+{
+	struct dwc3 *dwc = dep->dwc;
+	struct dwc3_gadget_ep_cmd_params params;
+	u32 cmd = DWC3_DEPCMD_CLEARSTALL;
+
+	if (dep->direction &&
+	    (dwc3_is_usb31(dwc) || (dwc->revision >= DWC3_REVISION_260A)))
+		cmd |= DWC3_DEPCMD_CLEARPENDIN;
+
+	memset(&params, 0, sizeof(params));
+
+	return dwc3_send_gadget_ep_cmd(dep, cmd, &params);
+}
+
 static dma_addr_t dwc3_trb_dma_offset(struct dwc3_ep *dep,
 		struct dwc3_trb *trb)
 {
@@ -1290,8 +1305,7 @@ int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol)
 		else
 			dep->flags |= DWC3_EP_STALL;
 	} else {
-		ret = dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_CLEARSTALL,
-				&params);
+		ret = dwc3_send_clear_stall_ep_cmd(dep);
 		if (ret)
 			dev_err(dwc->dev, "failed to clear STALL on %s\n",
 					dep->name);
@@ -2300,7 +2314,6 @@ static void dwc3_clear_stall_all_ep(struct dwc3 *dwc)
 
 	for (epnum = 1; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
 		struct dwc3_ep *dep;
-		struct dwc3_gadget_ep_cmd_params params;
 		int ret;
 
 		dep = dwc->eps[epnum];
@@ -2312,9 +2325,7 @@ static void dwc3_clear_stall_all_ep(struct dwc3 *dwc)
 
 		dep->flags &= ~DWC3_EP_STALL;
 
-		memset(&params, 0, sizeof(params));
-		ret = dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_CLEARSTALL,
-				&params);
+		ret = dwc3_send_clear_stall_ep_cmd(dep);
 		WARN_ON_ONCE(ret);
 	}
 }
-- 
2.8.2

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