diff mbox series

[v3,2/3] mt76usb: use synchronous msg for mcu command responses

Message ID 1550679320-14343-2-git-send-email-sgruszka@redhat.com (mailing list archive)
State Accepted
Delegated to: Kalle Valo
Headers show
Series [v3,1/3] mt76usb: allow mt76u_bulk_msg be used for reads | expand

Commit Message

Stanislaw Gruszka Feb. 20, 2019, 4:15 p.m. UTC
Use usb_bulk_msg for reading MCU command responses. This simplify code
a lot.

Together with 97a3005759c ("mt76usb: allow mt76u_bulk_msg be used
for reads") it also fix possible problems with rx data buffers
not being aligned and contained within single page. After doing
page_frag_alloc(1024) consecutive page_frag_alloc(PAGE_SIZE) will
alloc PAGE_SIZE buffer at PAGE_SIZE - 1024 offset.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
 drivers/net/wireless/mediatek/mt76/mt76.h          |  3 +-
 drivers/net/wireless/mediatek/mt76/mt76x0/usb.c    | 11 --------
 .../net/wireless/mediatek/mt76/mt76x02_usb_mcu.c   | 32 +++++++---------------
 drivers/net/wireless/mediatek/mt76/mt76x2/usb.c    | 11 --------
 drivers/net/wireless/mediatek/mt76/usb.c           |  1 -
 drivers/net/wireless/mediatek/mt76/usb_mcu.c       | 31 +++------------------
 6 files changed, 15 insertions(+), 74 deletions(-)

Comments

Lorenzo Bianconi Feb. 22, 2019, 9:53 a.m. UTC | #1
> Use usb_bulk_msg for reading MCU command responses. This simplify code
> a lot.
> 
> Together with 97a3005759c ("mt76usb: allow mt76u_bulk_msg be used
> for reads") it also fix possible problems with rx data buffers
> not being aligned and contained within single page. After doing
> page_frag_alloc(1024) consecutive page_frag_alloc(PAGE_SIZE) will
> alloc PAGE_SIZE buffer at PAGE_SIZE - 1024 offset.
> 
> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
> ---
>  drivers/net/wireless/mediatek/mt76/mt76.h          |  3 +-
>  drivers/net/wireless/mediatek/mt76/mt76x0/usb.c    | 11 --------
>  .../net/wireless/mediatek/mt76/mt76x02_usb_mcu.c   | 32 +++++++---------------
>  drivers/net/wireless/mediatek/mt76/mt76x2/usb.c    | 11 --------
>  drivers/net/wireless/mediatek/mt76/usb.c           |  1 -
>  drivers/net/wireless/mediatek/mt76/usb_mcu.c       | 31 +++------------------
>  6 files changed, 15 insertions(+), 74 deletions(-)
> 
> diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
> index 6092646014c4..c9b5eb9b0582 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt76.h
> +++ b/drivers/net/wireless/mediatek/mt76/mt76.h
> @@ -384,8 +384,7 @@ struct mt76_usb {
>  
>  	struct mt76u_mcu {
>  		struct mutex mutex;
> -		struct completion cmpl;

Hi Stanislaw,

I was reviewing this approach and I guess it is a little bit racey since now we
are not sure that when the device is removed or suspended the pending mcu commands
are terminated and we do not have any api to stop usb transactions.
Are we sure when we access mt76x02_dev/mt76_dev structure it has not been
already removed?
Maybe we need to maintain the completion in mt76u_mcu and use it to wait the mcu
commands are terminated.

Regards,
Lorenzo

> -		struct mt76u_buf res;
> +		u8 *data;
>  		u32 msg_seq;
>  
>  		/* multiple reads */
> diff --git a/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c b/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c
> index da9d05f6074d..f0c33890f1a5 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c
> @@ -311,13 +311,11 @@ static int __maybe_unused mt76x0_suspend(struct usb_interface *usb_intf,
>  					 pm_message_t state)
>  {
>  	struct mt76x02_dev *dev = usb_get_intfdata(usb_intf);
> -	struct mt76_usb *usb = &dev->mt76.usb;
>  
>  	mt76u_stop_queues(&dev->mt76);
>  	mt76x0u_mac_stop(dev);
>  	clear_bit(MT76_STATE_MCU_RUNNING, &dev->mt76.state);
>  	mt76x0_chip_onoff(dev, false, false);
> -	usb_kill_urb(usb->mcu.res.urb);
>  
>  	return 0;
>  }
> @@ -328,15 +326,6 @@ static int __maybe_unused mt76x0_resume(struct usb_interface *usb_intf)
>  	struct mt76_usb *usb = &dev->mt76.usb;
>  	int ret;
>  
> -	reinit_completion(&usb->mcu.cmpl);
> -	ret = mt76u_submit_buf(&dev->mt76, USB_DIR_IN,
> -			       MT_EP_IN_CMD_RESP,
> -			       &usb->mcu.res, GFP_KERNEL,
> -			       mt76u_mcu_complete_urb,
> -			       &usb->mcu.cmpl);
> -	if (ret < 0)
> -		goto err;
> -
>  	ret = mt76u_submit_rx_buffers(&dev->mt76);
>  	if (ret < 0)
>  		goto err;
> diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_usb_mcu.c b/drivers/net/wireless/mediatek/mt76/mt76x02_usb_mcu.c
> index f497c8e4332a..0cb8751321a1 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt76x02_usb_mcu.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt76x02_usb_mcu.c
> @@ -61,33 +61,21 @@ mt76x02u_multiple_mcu_reads(struct mt76_dev *dev, u8 *data, int len)
>  static int mt76x02u_mcu_wait_resp(struct mt76_dev *dev, u8 seq)
>  {
>  	struct mt76_usb *usb = &dev->usb;
> -	struct mt76u_buf *buf = &usb->mcu.res;
> -	struct urb *urb = buf->urb;
> -	u8 *data = buf->buf;
> -	int i, ret;
> +	u8 *data = usb->mcu.data;
> +	int i, len, ret;
>  	u32 rxfce;
>  
>  	for (i = 0; i < 5; i++) {
> -		if (!wait_for_completion_timeout(&usb->mcu.cmpl,
> -						 msecs_to_jiffies(300)))
> +		ret = mt76u_bulk_msg(dev, data, MCU_RESP_URB_SIZE, &len, 300);
> +		if (ret == -ETIMEDOUT)
>  			continue;
> -
> -		if (urb->status)
> -			return -EIO;
> +		if (ret)
> +			goto out;
>  
>  		if (usb->mcu.rp)
> -			mt76x02u_multiple_mcu_reads(dev, data + 4,
> -						    urb->actual_length - 8);
> +			mt76x02u_multiple_mcu_reads(dev, data + 4, len - 8);
>  
>  		rxfce = get_unaligned_le32(data);
> -		ret = mt76u_submit_buf(dev, USB_DIR_IN,
> -				       MT_EP_IN_CMD_RESP,
> -				       buf, GFP_KERNEL,
> -				       mt76u_mcu_complete_urb,
> -				       &usb->mcu.cmpl);
> -		if (ret)
> -			return ret;
> -
>  		if (seq == FIELD_GET(MT_RX_FCE_INFO_CMD_SEQ, rxfce) &&
>  		    FIELD_GET(MT_RX_FCE_INFO_EVT_TYPE, rxfce) == EVT_CMD_DONE)
>  			return 0;
> @@ -96,9 +84,9 @@ static int mt76x02u_mcu_wait_resp(struct mt76_dev *dev, u8 seq)
>  			FIELD_GET(MT_RX_FCE_INFO_EVT_TYPE, rxfce),
>  			seq, FIELD_GET(MT_RX_FCE_INFO_CMD_SEQ, rxfce));
>  	}
> -
> -	dev_err(dev->dev, "error: %s timed out\n", __func__);
> -	return -ETIMEDOUT;
> +out:
> +	dev_err(dev->dev, "error: %s failed with %d\n", __func__, ret);
> +	return ret;
>  }
>  
>  static int
> diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/usb.c b/drivers/net/wireless/mediatek/mt76/mt76x2/usb.c
> index f81a85e96922..ddb6b2c48e01 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt76x2/usb.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt76x2/usb.c
> @@ -100,11 +100,9 @@ static int __maybe_unused mt76x2u_suspend(struct usb_interface *intf,
>  					  pm_message_t state)
>  {
>  	struct mt76x02_dev *dev = usb_get_intfdata(intf);
> -	struct mt76_usb *usb = &dev->mt76.usb;
>  
>  	mt76u_stop_queues(&dev->mt76);
>  	mt76x2u_stop_hw(dev);
> -	usb_kill_urb(usb->mcu.res.urb);
>  
>  	return 0;
>  }
> @@ -115,15 +113,6 @@ static int __maybe_unused mt76x2u_resume(struct usb_interface *intf)
>  	struct mt76_usb *usb = &dev->mt76.usb;
>  	int err;
>  
> -	reinit_completion(&usb->mcu.cmpl);
> -	err = mt76u_submit_buf(&dev->mt76, USB_DIR_IN,
> -			       MT_EP_IN_CMD_RESP,
> -			       &usb->mcu.res, GFP_KERNEL,
> -			       mt76u_mcu_complete_urb,
> -			       &usb->mcu.cmpl);
> -	if (err < 0)
> -		goto err;
> -
>  	err = mt76u_submit_rx_buffers(&dev->mt76);
>  	if (err < 0)
>  		goto err;
> diff --git a/drivers/net/wireless/mediatek/mt76/usb.c b/drivers/net/wireless/mediatek/mt76/usb.c
> index 78191968b4fa..5c3b7f735aae 100644
> --- a/drivers/net/wireless/mediatek/mt76/usb.c
> +++ b/drivers/net/wireless/mediatek/mt76/usb.c
> @@ -933,7 +933,6 @@ int mt76u_init(struct mt76_dev *dev,
>  	INIT_DELAYED_WORK(&usb->stat_work, mt76u_tx_status_data);
>  	skb_queue_head_init(&dev->rx_skb[MT_RXQ_MAIN]);
>  
> -	init_completion(&usb->mcu.cmpl);
>  	mutex_init(&usb->mcu.mutex);
>  
>  	mutex_init(&usb->usb_ctrl_mtx);
> diff --git a/drivers/net/wireless/mediatek/mt76/usb_mcu.c b/drivers/net/wireless/mediatek/mt76/usb_mcu.c
> index 72c8607da4b4..747231edc57d 100644
> --- a/drivers/net/wireless/mediatek/mt76/usb_mcu.c
> +++ b/drivers/net/wireless/mediatek/mt76/usb_mcu.c
> @@ -16,42 +16,19 @@
>  
>  #include "mt76.h"
>  
> -void mt76u_mcu_complete_urb(struct urb *urb)
> -{
> -	struct completion *cmpl = urb->context;
> -
> -	complete(cmpl);
> -}
> -EXPORT_SYMBOL_GPL(mt76u_mcu_complete_urb);
> -
>  int mt76u_mcu_init_rx(struct mt76_dev *dev)
>  {
>  	struct mt76_usb *usb = &dev->usb;
> -	int err;
>  
> -	err = mt76u_buf_alloc(dev, &usb->mcu.res, MCU_RESP_URB_SIZE,
> -			      MCU_RESP_URB_SIZE, GFP_KERNEL);
> -	if (err < 0)
> -		return err;
> -
> -	err = mt76u_submit_buf(dev, USB_DIR_IN, MT_EP_IN_CMD_RESP,
> -			       &usb->mcu.res, GFP_KERNEL,
> -			       mt76u_mcu_complete_urb,
> -			       &usb->mcu.cmpl);
> -	if (err < 0)
> -		mt76u_buf_free(&usb->mcu.res);
> -
> -	return err;
> +	usb->mcu.data = kmalloc(MCU_RESP_URB_SIZE, GFP_KERNEL);
> +	return usb->mcu.data ? 0 : -ENOMEM;
>  }
>  EXPORT_SYMBOL_GPL(mt76u_mcu_init_rx);
>  
>  void mt76u_mcu_deinit(struct mt76_dev *dev)
>  {
> -	struct mt76u_buf *buf = &dev->usb.mcu.res;
> +	struct mt76_usb *usb = &dev->usb;
>  
> -	if (buf->urb) {
> -		usb_kill_urb(buf->urb);
> -		mt76u_buf_free(buf);
> -	}
> +	kfree(usb->mcu.data);
>  }
>  EXPORT_SYMBOL_GPL(mt76u_mcu_deinit);
> -- 
> 2.7.5
>
Stanislaw Gruszka Feb. 22, 2019, 11:54 a.m. UTC | #2
On Fri, Feb 22, 2019 at 10:53:19AM +0100, Lorenzo Bianconi wrote:
> > Use usb_bulk_msg for reading MCU command responses. This simplify code
> > a lot.
> > 
> > Together with 97a3005759c ("mt76usb: allow mt76u_bulk_msg be used
> > for reads") it also fix possible problems with rx data buffers
> > not being aligned and contained within single page. After doing
> > page_frag_alloc(1024) consecutive page_frag_alloc(PAGE_SIZE) will
> > alloc PAGE_SIZE buffer at PAGE_SIZE - 1024 offset.
> > 
> > Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
> > ---
> >  drivers/net/wireless/mediatek/mt76/mt76.h          |  3 +-
> >  drivers/net/wireless/mediatek/mt76/mt76x0/usb.c    | 11 --------
> >  .../net/wireless/mediatek/mt76/mt76x02_usb_mcu.c   | 32 +++++++---------------
> >  drivers/net/wireless/mediatek/mt76/mt76x2/usb.c    | 11 --------
> >  drivers/net/wireless/mediatek/mt76/usb.c           |  1 -
> >  drivers/net/wireless/mediatek/mt76/usb_mcu.c       | 31 +++------------------
> >  6 files changed, 15 insertions(+), 74 deletions(-)
> > 
> > diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
> > index 6092646014c4..c9b5eb9b0582 100644
> > --- a/drivers/net/wireless/mediatek/mt76/mt76.h
> > +++ b/drivers/net/wireless/mediatek/mt76/mt76.h
> > @@ -384,8 +384,7 @@ struct mt76_usb {
> >  
> >  	struct mt76u_mcu {
> >  		struct mutex mutex;
> > -		struct completion cmpl;
> 
> Hi Stanislaw,
> 
> I was reviewing this approach and I guess it is a little bit racey since now we
> are not sure that when the device is removed or suspended the pending mcu commands
> are terminated and we do not have any api to stop usb transactions.
> Are we sure when we access mt76x02_dev/mt76_dev structure it has not been
> already removed?
> Maybe we need to maintain the completion in mt76u_mcu and use it to wait the mcu
> commands are terminated.

I don't think so. On suspend we do mt76xxu_mac_stop() which access registers
using mcu commands, all should be synchronized by mcu->mutex . All other
process that could use mcu command should be already stopped. Actually suspend
can be simplified.

Device remove should be properly handled by -ENODEV error returned by
usb_bulk_msg.

Stanislaw
Lorenzo Bianconi Feb. 22, 2019, noon UTC | #3
> On Fri, Feb 22, 2019 at 10:53:19AM +0100, Lorenzo Bianconi wrote:
> > > Use usb_bulk_msg for reading MCU command responses. This simplify code
> > > a lot.
> > > 
> > > Together with 97a3005759c ("mt76usb: allow mt76u_bulk_msg be used
> > > for reads") it also fix possible problems with rx data buffers
> > > not being aligned and contained within single page. After doing
> > > page_frag_alloc(1024) consecutive page_frag_alloc(PAGE_SIZE) will
> > > alloc PAGE_SIZE buffer at PAGE_SIZE - 1024 offset.
> > > 
> > > Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
> > > ---
> > >  drivers/net/wireless/mediatek/mt76/mt76.h          |  3 +-
> > >  drivers/net/wireless/mediatek/mt76/mt76x0/usb.c    | 11 --------
> > >  .../net/wireless/mediatek/mt76/mt76x02_usb_mcu.c   | 32 +++++++---------------
> > >  drivers/net/wireless/mediatek/mt76/mt76x2/usb.c    | 11 --------
> > >  drivers/net/wireless/mediatek/mt76/usb.c           |  1 -
> > >  drivers/net/wireless/mediatek/mt76/usb_mcu.c       | 31 +++------------------
> > >  6 files changed, 15 insertions(+), 74 deletions(-)
> > > 
> > > diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
> > > index 6092646014c4..c9b5eb9b0582 100644
> > > --- a/drivers/net/wireless/mediatek/mt76/mt76.h
> > > +++ b/drivers/net/wireless/mediatek/mt76/mt76.h
> > > @@ -384,8 +384,7 @@ struct mt76_usb {
> > >  
> > >  	struct mt76u_mcu {
> > >  		struct mutex mutex;
> > > -		struct completion cmpl;
> > 
> > Hi Stanislaw,
> > 
> > I was reviewing this approach and I guess it is a little bit racey since now we
> > are not sure that when the device is removed or suspended the pending mcu commands
> > are terminated and we do not have any api to stop usb transactions.
> > Are we sure when we access mt76x02_dev/mt76_dev structure it has not been
> > already removed?
> > Maybe we need to maintain the completion in mt76u_mcu and use it to wait the mcu
> > commands are terminated.
> 
> I don't think so. On suspend we do mt76xxu_mac_stop() which access registers
> using mcu commands, all should be synchronized by mcu->mutex . All other
> process that could use mcu command should be already stopped. Actually suspend
> can be simplified.

ack, I missed mcu->mutex. Thx.

Regards,
Lorenzo

> 
> Device remove should be properly handled by -ENODEV error returned by
> usb_bulk_msg.
> 
> Stanislaw
diff mbox series

Patch

diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index 6092646014c4..c9b5eb9b0582 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -384,8 +384,7 @@  struct mt76_usb {
 
 	struct mt76u_mcu {
 		struct mutex mutex;
-		struct completion cmpl;
-		struct mt76u_buf res;
+		u8 *data;
 		u32 msg_seq;
 
 		/* multiple reads */
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c b/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c
index da9d05f6074d..f0c33890f1a5 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c
@@ -311,13 +311,11 @@  static int __maybe_unused mt76x0_suspend(struct usb_interface *usb_intf,
 					 pm_message_t state)
 {
 	struct mt76x02_dev *dev = usb_get_intfdata(usb_intf);
-	struct mt76_usb *usb = &dev->mt76.usb;
 
 	mt76u_stop_queues(&dev->mt76);
 	mt76x0u_mac_stop(dev);
 	clear_bit(MT76_STATE_MCU_RUNNING, &dev->mt76.state);
 	mt76x0_chip_onoff(dev, false, false);
-	usb_kill_urb(usb->mcu.res.urb);
 
 	return 0;
 }
@@ -328,15 +326,6 @@  static int __maybe_unused mt76x0_resume(struct usb_interface *usb_intf)
 	struct mt76_usb *usb = &dev->mt76.usb;
 	int ret;
 
-	reinit_completion(&usb->mcu.cmpl);
-	ret = mt76u_submit_buf(&dev->mt76, USB_DIR_IN,
-			       MT_EP_IN_CMD_RESP,
-			       &usb->mcu.res, GFP_KERNEL,
-			       mt76u_mcu_complete_urb,
-			       &usb->mcu.cmpl);
-	if (ret < 0)
-		goto err;
-
 	ret = mt76u_submit_rx_buffers(&dev->mt76);
 	if (ret < 0)
 		goto err;
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_usb_mcu.c b/drivers/net/wireless/mediatek/mt76/mt76x02_usb_mcu.c
index f497c8e4332a..0cb8751321a1 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x02_usb_mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02_usb_mcu.c
@@ -61,33 +61,21 @@  mt76x02u_multiple_mcu_reads(struct mt76_dev *dev, u8 *data, int len)
 static int mt76x02u_mcu_wait_resp(struct mt76_dev *dev, u8 seq)
 {
 	struct mt76_usb *usb = &dev->usb;
-	struct mt76u_buf *buf = &usb->mcu.res;
-	struct urb *urb = buf->urb;
-	u8 *data = buf->buf;
-	int i, ret;
+	u8 *data = usb->mcu.data;
+	int i, len, ret;
 	u32 rxfce;
 
 	for (i = 0; i < 5; i++) {
-		if (!wait_for_completion_timeout(&usb->mcu.cmpl,
-						 msecs_to_jiffies(300)))
+		ret = mt76u_bulk_msg(dev, data, MCU_RESP_URB_SIZE, &len, 300);
+		if (ret == -ETIMEDOUT)
 			continue;
-
-		if (urb->status)
-			return -EIO;
+		if (ret)
+			goto out;
 
 		if (usb->mcu.rp)
-			mt76x02u_multiple_mcu_reads(dev, data + 4,
-						    urb->actual_length - 8);
+			mt76x02u_multiple_mcu_reads(dev, data + 4, len - 8);
 
 		rxfce = get_unaligned_le32(data);
-		ret = mt76u_submit_buf(dev, USB_DIR_IN,
-				       MT_EP_IN_CMD_RESP,
-				       buf, GFP_KERNEL,
-				       mt76u_mcu_complete_urb,
-				       &usb->mcu.cmpl);
-		if (ret)
-			return ret;
-
 		if (seq == FIELD_GET(MT_RX_FCE_INFO_CMD_SEQ, rxfce) &&
 		    FIELD_GET(MT_RX_FCE_INFO_EVT_TYPE, rxfce) == EVT_CMD_DONE)
 			return 0;
@@ -96,9 +84,9 @@  static int mt76x02u_mcu_wait_resp(struct mt76_dev *dev, u8 seq)
 			FIELD_GET(MT_RX_FCE_INFO_EVT_TYPE, rxfce),
 			seq, FIELD_GET(MT_RX_FCE_INFO_CMD_SEQ, rxfce));
 	}
-
-	dev_err(dev->dev, "error: %s timed out\n", __func__);
-	return -ETIMEDOUT;
+out:
+	dev_err(dev->dev, "error: %s failed with %d\n", __func__, ret);
+	return ret;
 }
 
 static int
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/usb.c b/drivers/net/wireless/mediatek/mt76/mt76x2/usb.c
index f81a85e96922..ddb6b2c48e01 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x2/usb.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x2/usb.c
@@ -100,11 +100,9 @@  static int __maybe_unused mt76x2u_suspend(struct usb_interface *intf,
 					  pm_message_t state)
 {
 	struct mt76x02_dev *dev = usb_get_intfdata(intf);
-	struct mt76_usb *usb = &dev->mt76.usb;
 
 	mt76u_stop_queues(&dev->mt76);
 	mt76x2u_stop_hw(dev);
-	usb_kill_urb(usb->mcu.res.urb);
 
 	return 0;
 }
@@ -115,15 +113,6 @@  static int __maybe_unused mt76x2u_resume(struct usb_interface *intf)
 	struct mt76_usb *usb = &dev->mt76.usb;
 	int err;
 
-	reinit_completion(&usb->mcu.cmpl);
-	err = mt76u_submit_buf(&dev->mt76, USB_DIR_IN,
-			       MT_EP_IN_CMD_RESP,
-			       &usb->mcu.res, GFP_KERNEL,
-			       mt76u_mcu_complete_urb,
-			       &usb->mcu.cmpl);
-	if (err < 0)
-		goto err;
-
 	err = mt76u_submit_rx_buffers(&dev->mt76);
 	if (err < 0)
 		goto err;
diff --git a/drivers/net/wireless/mediatek/mt76/usb.c b/drivers/net/wireless/mediatek/mt76/usb.c
index 78191968b4fa..5c3b7f735aae 100644
--- a/drivers/net/wireless/mediatek/mt76/usb.c
+++ b/drivers/net/wireless/mediatek/mt76/usb.c
@@ -933,7 +933,6 @@  int mt76u_init(struct mt76_dev *dev,
 	INIT_DELAYED_WORK(&usb->stat_work, mt76u_tx_status_data);
 	skb_queue_head_init(&dev->rx_skb[MT_RXQ_MAIN]);
 
-	init_completion(&usb->mcu.cmpl);
 	mutex_init(&usb->mcu.mutex);
 
 	mutex_init(&usb->usb_ctrl_mtx);
diff --git a/drivers/net/wireless/mediatek/mt76/usb_mcu.c b/drivers/net/wireless/mediatek/mt76/usb_mcu.c
index 72c8607da4b4..747231edc57d 100644
--- a/drivers/net/wireless/mediatek/mt76/usb_mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/usb_mcu.c
@@ -16,42 +16,19 @@ 
 
 #include "mt76.h"
 
-void mt76u_mcu_complete_urb(struct urb *urb)
-{
-	struct completion *cmpl = urb->context;
-
-	complete(cmpl);
-}
-EXPORT_SYMBOL_GPL(mt76u_mcu_complete_urb);
-
 int mt76u_mcu_init_rx(struct mt76_dev *dev)
 {
 	struct mt76_usb *usb = &dev->usb;
-	int err;
 
-	err = mt76u_buf_alloc(dev, &usb->mcu.res, MCU_RESP_URB_SIZE,
-			      MCU_RESP_URB_SIZE, GFP_KERNEL);
-	if (err < 0)
-		return err;
-
-	err = mt76u_submit_buf(dev, USB_DIR_IN, MT_EP_IN_CMD_RESP,
-			       &usb->mcu.res, GFP_KERNEL,
-			       mt76u_mcu_complete_urb,
-			       &usb->mcu.cmpl);
-	if (err < 0)
-		mt76u_buf_free(&usb->mcu.res);
-
-	return err;
+	usb->mcu.data = kmalloc(MCU_RESP_URB_SIZE, GFP_KERNEL);
+	return usb->mcu.data ? 0 : -ENOMEM;
 }
 EXPORT_SYMBOL_GPL(mt76u_mcu_init_rx);
 
 void mt76u_mcu_deinit(struct mt76_dev *dev)
 {
-	struct mt76u_buf *buf = &dev->usb.mcu.res;
+	struct mt76_usb *usb = &dev->usb;
 
-	if (buf->urb) {
-		usb_kill_urb(buf->urb);
-		mt76u_buf_free(buf);
-	}
+	kfree(usb->mcu.data);
 }
 EXPORT_SYMBOL_GPL(mt76u_mcu_deinit);