From: Chunfeng Yun <chunfeng.yun@mediatek.com>
Date: Mon, 17 Apr 2023 02:51:57 +0000 (+0800)
Subject: usb: mtu3: give back request when rx error happens
X-Git-Tag: v6.6.7~2985^2~15
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c507565aac2e8c4ca8dd36afcd40e15e4b459d93;p=platform%2Fkernel%2Flinux-starfive.git

usb: mtu3: give back request when rx error happens

When the Rx enconnter errors, currently, only print error logs, that
may cause class driver's RX halt, shall give back the request with
error status meanwhile.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20230417025203.18097-1-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/mtu3/mtu3_qmu.c b/drivers/usb/mtu3/mtu3_qmu.c
index a2fdab8..a4da1af 100644
--- a/drivers/usb/mtu3/mtu3_qmu.c
+++ b/drivers/usb/mtu3/mtu3_qmu.c
@@ -467,6 +467,37 @@ static void qmu_tx_zlp_error_handler(struct mtu3 *mtu, u8 epnum)
 }
 
 /*
+ * when rx error happens (except zlperr), QMU will stop, and RQCPR saves
+ * the GPD encountered error, Done irq will arise after resuming QMU again.
+ */
+static void qmu_error_rx(struct mtu3 *mtu, u8 epnum)
+{
+	struct mtu3_ep *mep = mtu->out_eps + epnum;
+	struct mtu3_gpd_ring *ring = &mep->gpd_ring;
+	struct qmu_gpd *gpd_current = NULL;
+	struct mtu3_request *mreq;
+	dma_addr_t cur_gpd_dma;
+
+	cur_gpd_dma = read_rxq_cur_addr(mtu->mac_base, epnum);
+	gpd_current = gpd_dma_to_virt(ring, cur_gpd_dma);
+
+	mreq = next_request(mep);
+	if (!mreq || mreq->gpd != gpd_current) {
+		dev_err(mtu->dev, "no correct RX req is found\n");
+		return;
+	}
+
+	mreq->request.status = -EAGAIN;
+
+	/* by pass the current GDP */
+	gpd_current->dw0_info |= cpu_to_le32(GPD_FLAGS_BPS | GPD_FLAGS_HWO);
+	mtu3_qmu_resume(mep);
+
+	dev_dbg(mtu->dev, "%s EP%d, current=%p, req=%p\n",
+		__func__, epnum, gpd_current, mreq);
+}
+
+/*
  * NOTE: request list maybe is already empty as following case:
  * queue_tx --> qmu_interrupt(clear interrupt pending, schedule tasklet)-->
  * queue_tx --> process_tasklet(meanwhile, the second one is transferred,
@@ -571,14 +602,18 @@ static void qmu_exception_isr(struct mtu3 *mtu, u32 qmu_status)
 
 	if ((qmu_status & RXQ_CSERR_INT) || (qmu_status & RXQ_LENERR_INT)) {
 		errval = mtu3_readl(mbase, U3D_RQERRIR0);
+		mtu3_writel(mbase, U3D_RQERRIR0, errval);
+
 		for (i = 1; i < mtu->num_eps; i++) {
 			if (errval & QMU_RX_CS_ERR(i))
 				dev_err(mtu->dev, "Rx %d CS error!\n", i);
 
 			if (errval & QMU_RX_LEN_ERR(i))
 				dev_err(mtu->dev, "RX %d Length error\n", i);
+
+			if (errval & (QMU_RX_CS_ERR(i) | QMU_RX_LEN_ERR(i)))
+				qmu_error_rx(mtu, i);
 		}
-		mtu3_writel(mbase, U3D_RQERRIR0, errval);
 	}
 
 	if (qmu_status & RXQ_ZLPERR_INT) {