[PATCH v2 1/7] usb: mtu3: give back request when rx error happens

[PATCH v2 1/7] usb: mtu3: give back request when rx error happens

[Chunfeng Yun]

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>
---
v2: remove @req suggested by AngeloGioacchino
---
 drivers/usb/mtu3/mtu3_qmu.c | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/mtu3/mtu3_qmu.c b/drivers/usb/mtu3/mtu3_qmu.c
index a2fdab8b63b2..a4da1af0b2c0 100644
--- a/drivers/usb/mtu3/mtu3_qmu.c
+++ b/drivers/usb/mtu3/mtu3_qmu.c
@@ -466,6 +466,37 @@ static void qmu_tx_zlp_error_handler(struct mtu3 *mtu, u8 epnum)
 	mtu3_qmu_resume(mep);
 }
 
+/*
+ * 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)-->
@@ -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) {
-- 
2.18.0

[PATCH v2 2/7] usb: mtu3: use boolean return value

[Chunfeng Yun]

Prefer to use boolean value due to gpd_ring_empty() return true or false.
See "16) Function return values and names" in coding-style.rst

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2: add Reviewed-by AngeloGioacchino
---
 drivers/usb/mtu3/mtu3_qmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/mtu3/mtu3_qmu.c b/drivers/usb/mtu3/mtu3_qmu.c
index a4da1af0b2c0..6be4977a5db5 100644
--- a/drivers/usb/mtu3/mtu3_qmu.c
+++ b/drivers/usb/mtu3/mtu3_qmu.c
@@ -221,7 +221,7 @@ static struct qmu_gpd *advance_deq_gpd(struct mtu3_gpd_ring *ring)
 }
 
 /* check if a ring is emtpy */
-static int gpd_ring_empty(struct mtu3_gpd_ring *ring)
+static bool gpd_ring_empty(struct mtu3_gpd_ring *ring)
 {
 	struct qmu_gpd *enq = ring->enqueue;
 	struct qmu_gpd *next;
-- 
2.18.0

[PATCH v2 3/7] usb: mtu3: fix kernel panic at qmu transfer done irq handler

[Chunfeng Yun]

When handle qmu transfer irq, it will unlock @mtu->lock before give back
request, if another thread handle disconnect event at the same time, and
try to disable ep, it may lock @mtu->lock and free qmu ring, then qmu
irq hanlder may get a NULL gpd, avoid the KE by checking gpd's value before
handling it.

e.g.
qmu done irq on cpu0                 thread running on cpu1

qmu_done_tx()
  handle gpd [0]
    mtu3_requ_complete()        mtu3_gadget_ep_disable()
      unlock @mtu->lock
        give back request         lock @mtu->lock
                                    mtu3_ep_disable()
                                      mtu3_gpd_ring_free()
                                   unlock @mtu->lock
      lock @mtu->lock
    get next gpd [1]

[1]: goto [0] to handle next gpd, and next gpd may be NULL.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2: fix typo suggested by AngeloGioacchino
---
 drivers/usb/mtu3/mtu3_qmu.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/mtu3/mtu3_qmu.c b/drivers/usb/mtu3/mtu3_qmu.c
index 6be4977a5db5..3d77408e3133 100644
--- a/drivers/usb/mtu3/mtu3_qmu.c
+++ b/drivers/usb/mtu3/mtu3_qmu.c
@@ -210,6 +210,7 @@ static struct qmu_gpd *advance_enq_gpd(struct mtu3_gpd_ring *ring)
 	return ring->enqueue;
 }
 
+/* @dequeue may be NULL if ring is unallocated or freed */
 static struct qmu_gpd *advance_deq_gpd(struct mtu3_gpd_ring *ring)
 {
 	if (ring->dequeue < ring->end)
@@ -522,7 +523,7 @@ static void qmu_done_tx(struct mtu3 *mtu, u8 epnum)
 	dev_dbg(mtu->dev, "%s EP%d, last=%p, current=%p, enq=%p\n",
 		__func__, epnum, gpd, gpd_current, ring->enqueue);
 
-	while (gpd != gpd_current && !GET_GPD_HWO(gpd)) {
+	while (gpd && gpd != gpd_current && !GET_GPD_HWO(gpd)) {
 
 		mreq = next_request(mep);
 
@@ -561,7 +562,7 @@ static void qmu_done_rx(struct mtu3 *mtu, u8 epnum)
 	dev_dbg(mtu->dev, "%s EP%d, last=%p, current=%p, enq=%p\n",
 		__func__, epnum, gpd, gpd_current, ring->enqueue);
 
-	while (gpd != gpd_current && !GET_GPD_HWO(gpd)) {
+	while (gpd && gpd != gpd_current && !GET_GPD_HWO(gpd)) {
 
 		mreq = next_request(mep);
 
-- 
2.18.0

[PATCH v2 4/7] usb: mtu3: unlock @mtu->lock just before giving back request

[Chunfeng Yun]

No need unlock @mtu->lock when unmap request, unlock it just before
giving back request, due to we do not lock this spinlock when map
the request.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2: add Reviewed-by AngeloGioacchino
---

 drivers/usb/mtu3/mtu3_gadget.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/mtu3/mtu3_gadget.c b/drivers/usb/mtu3/mtu3_gadget.c
index c0264d5426bf..ad0eeac4332d 100644
--- a/drivers/usb/mtu3/mtu3_gadget.c
+++ b/drivers/usb/mtu3/mtu3_gadget.c
@@ -23,7 +23,6 @@ __acquires(mep->mtu->lock)
 		req->status = status;
 
 	trace_mtu3_req_complete(mreq);
-	spin_unlock(&mtu->lock);
 
 	/* ep0 makes use of PIO, needn't unmap it */
 	if (mep->epnum)
@@ -32,6 +31,7 @@ __acquires(mep->mtu->lock)
 	dev_dbg(mtu->dev, "%s complete req: %p, sts %d, %d/%d\n",
 		mep->name, req, req->status, req->actual, req->length);
 
+	spin_unlock(&mtu->lock);
 	usb_gadget_giveback_request(&mep->ep, req);
 	spin_lock(&mtu->lock);
 }
-- 
2.18.0

[PATCH v2 5/7] usb: mtu3: expose role-switch control to userspace

[Chunfeng Yun]

The allow_userspace_control flag enables manual role switch from userspace,
turn this feature on like several other USB DRD controller drivers.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2: add Reviewed-by AngeloGioacchino
---
 drivers/usb/mtu3/mtu3_dr.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/mtu3/mtu3_dr.c b/drivers/usb/mtu3/mtu3_dr.c
index 9b8aded3d95e..8191b7ed3852 100644
--- a/drivers/usb/mtu3/mtu3_dr.c
+++ b/drivers/usb/mtu3/mtu3_dr.c
@@ -294,6 +294,7 @@ static int ssusb_role_sw_register(struct otg_switch_mtk *otg_sx)
 	role_sx_desc.get = ssusb_role_sw_get;
 	role_sx_desc.fwnode = dev_fwnode(dev);
 	role_sx_desc.driver_data = ssusb;
+	role_sx_desc.allow_userspace_control = true;
 	otg_sx->role_sw = usb_role_switch_register(dev, &role_sx_desc);
 	if (IS_ERR(otg_sx->role_sw))
 		return PTR_ERR(otg_sx->role_sw);
-- 
2.18.0

[PATCH v2 6/7] dt-bindings: usb: mtu3: add two optional clocks

[Chunfeng Yun]

Add optional clock 'xhci_ck' and 'frmcnt_ck';
Add optional property "assigned-clock" and "assigned-clock-parents";

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2: remove assigned-clocks* properties suggested by Rob
---
 Documentation/devicetree/bindings/usb/mediatek,mtu3.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtu3.yaml b/Documentation/devicetree/bindings/usb/mediatek,mtu3.yaml
index d2655173e108..3d403d944453 100644
--- a/Documentation/devicetree/bindings/usb/mediatek,mtu3.yaml
+++ b/Documentation/devicetree/bindings/usb/mediatek,mtu3.yaml
@@ -66,6 +66,8 @@ properties:
       - description: Reference clock used by low power mode etc
       - description: Mcu bus clock for register access
       - description: DMA bus clock for data transfer
+      - description: DRD controller clock
+      - description: Frame count clock
 
   clock-names:
     minItems: 1
@@ -74,6 +76,8 @@ properties:
       - const: ref_ck
       - const: mcu_ck
       - const: dma_ck
+      - const: xhci_ck
+      - const: frmcnt_ck
 
   phys:
     description:
-- 
2.18.0

[PATCH v2 7/7] usb: mtu3: add optional clock xhci_ck and frmcnt_ck

[Chunfeng Yun]

Add optional clock 'xhci_ck' which is usually the same as sys_ck, but
some SoC use two separated clocks when the controller supports dual
role mode;
Add optional clock 'frmcnt_ck' used on 4nm or advanced process SoC.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2: no changes
---
 drivers/usb/mtu3/mtu3.h      | 2 +-
 drivers/usb/mtu3/mtu3_plat.c | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/mtu3/mtu3.h b/drivers/usb/mtu3/mtu3.h
index 2d7b57e07eee..b4a7662dded5 100644
--- a/drivers/usb/mtu3/mtu3.h
+++ b/drivers/usb/mtu3/mtu3.h
@@ -90,7 +90,7 @@ struct mtu3_request;
  */
 #define EP0_RESPONSE_BUF  6
 
-#define BULK_CLKS_CNT	4
+#define BULK_CLKS_CNT	6
 
 /* device operated link and speed got from DEVICE_CONF register */
 enum mtu3_speed {
diff --git a/drivers/usb/mtu3/mtu3_plat.c b/drivers/usb/mtu3/mtu3_plat.c
index d78ae52b4e26..6f264b129243 100644
--- a/drivers/usb/mtu3/mtu3_plat.c
+++ b/drivers/usb/mtu3/mtu3_plat.c
@@ -234,6 +234,8 @@ static int get_ssusb_rscs(struct platform_device *pdev, struct ssusb_mtk *ssusb)
 	clks[1].id = "ref_ck";
 	clks[2].id = "mcu_ck";
 	clks[3].id = "dma_ck";
+	clks[4].id = "xhci_ck";
+	clks[5].id = "frmcnt_ck";
 	ret = devm_clk_bulk_get_optional(dev, BULK_CLKS_CNT, clks);
 	if (ret)
 		return ret;
-- 
2.18.0

Re: [PATCH v2 3/7] usb: mtu3: fix kernel panic at qmu transfer done irq handler

[AngeloGioacchino Del Regno]

Il 07/04/23 10:29, Chunfeng Yun ha scritto:
> When handle qmu transfer irq, it will unlock @mtu->lock before give back
> request, if another thread handle disconnect event at the same time, and
> try to disable ep, it may lock @mtu->lock and free qmu ring, then qmu
> irq hanlder may get a NULL gpd, avoid the KE by checking gpd's value before
> handling it.
> 
> e.g.
> qmu done irq on cpu0                 thread running on cpu1
> 
> qmu_done_tx()
>    handle gpd [0]
>      mtu3_requ_complete()        mtu3_gadget_ep_disable()
>        unlock @mtu->lock
>          give back request         lock @mtu->lock
>                                      mtu3_ep_disable()
>                                        mtu3_gpd_ring_free()
>                                     unlock @mtu->lock
>        lock @mtu->lock
>      get next gpd [1]
> 
> [1]: goto [0] to handle next gpd, and next gpd may be NULL.
> 
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>

NACK. You still miss the Fixes tag.

Regards,
Angelo

Re: [PATCH v2 6/7] dt-bindings: usb: mtu3: add two optional clocks

[Rob Herring]

On Fri, 07 Apr 2023 16:29:36 +0800, Chunfeng Yun wrote:
> Add optional clock 'xhci_ck' and 'frmcnt_ck';
> Add optional property "assigned-clock" and "assigned-clock-parents";
> 
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> ---
> v2: remove assigned-clocks* properties suggested by Rob
> ---
>  Documentation/devicetree/bindings/usb/mediatek,mtu3.yaml | 4 ++++
>  1 file changed, 4 insertions(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v2 3/7] usb: mtu3: fix kernel panic at qmu transfer done irq handler

[Chunfeng Yun (云春峰)]

On Fri, 2023-04-07 at 11:09 +0200, AngeloGioacchino Del Regno wrote:
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> Il 07/04/23 10:29, Chunfeng Yun ha scritto:
> > When handle qmu transfer irq, it will unlock @mtu->lock before give
> > back
> > request, if another thread handle disconnect event at the same
> > time, and
> > try to disable ep, it may lock @mtu->lock and free qmu ring, then
> > qmu
> > irq hanlder may get a NULL gpd, avoid the KE by checking gpd's
> > value before
> > handling it.
> > 
> > e.g.
> > qmu done irq on cpu0                 thread running on cpu1
> > 
> > qmu_done_tx()
> >    handle gpd [0]
> >      mtu3_requ_complete()        mtu3_gadget_ep_disable()
> >        unlock @mtu->lock
> >          give back request         lock @mtu->lock
> >                                      mtu3_ep_disable()
> >                                        mtu3_gpd_ring_free()
> >                                     unlock @mtu->lock
> >        lock @mtu->lock
> >      get next gpd [1]
> > 
> > [1]: goto [0] to handle next gpd, and next gpd may be NULL.
> > 
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> 
> NACK. You still miss the Fixes tag.
Ok, I'll add it, thanks

> 
> Regards,
> Angelo
>