diff mbox series

usb: musb: fix MUSB_QUIRK_B_DISCONNECT_99 handling

Message ID 20210528140446.278076-1-thomas.petazzoni@bootlin.com
State New
Headers show
Series usb: musb: fix MUSB_QUIRK_B_DISCONNECT_99 handling | expand

Commit Message

Thomas Petazzoni May 28, 2021, 2:04 p.m. UTC
In commit 92af4fc6ec33 ("usb: musb: Fix suspend with devices
connected for a64"), the logic to support the
MUSB_QUIRK_B_DISCONNECT_99 quirk was modified to only conditionally
schedule the musb->irq_work delayed work.

This commit badly breaks ECM Gadget on AM335X. Indeed, with this
commit, one can observe massive packet loss:

$ ping 192.168.0.100
...
15 packets transmitted, 3 received, 80% packet loss, time 14316ms

Reverting this commit brings back a properly functioning ECM
Gadget. An analysis of the commit seems to indicate that a mistake was
made: the previous code was not falling through into the
MUSB_QUIRK_B_INVALID_VBUS_91, but now it is, unless the condition is
taken.

Changing the logic to be as it was before the problematic commit *and*
only conditionally scheduling musb->irq_work resolves the regression:

$ ping 192.168.0.100
...
64 packets transmitted, 64 received, 0% packet loss, time 64475ms

Fixes: 92af4fc6ec33 ("usb: musb: Fix suspend with devices connected for a64")
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: stable@vger.kernel.org
---
 drivers/usb/musb/musb_core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Comments

Alexandre Belloni May 28, 2021, 3:35 p.m. UTC | #1
On 28/05/2021 16:04:46+0200, Thomas Petazzoni wrote:
> In commit 92af4fc6ec33 ("usb: musb: Fix suspend with devices
> connected for a64"), the logic to support the
> MUSB_QUIRK_B_DISCONNECT_99 quirk was modified to only conditionally
> schedule the musb->irq_work delayed work.
> 
> This commit badly breaks ECM Gadget on AM335X. Indeed, with this
> commit, one can observe massive packet loss:
> 
> $ ping 192.168.0.100
> ...
> 15 packets transmitted, 3 received, 80% packet loss, time 14316ms
> 
> Reverting this commit brings back a properly functioning ECM
> Gadget. An analysis of the commit seems to indicate that a mistake was
> made: the previous code was not falling through into the
> MUSB_QUIRK_B_INVALID_VBUS_91, but now it is, unless the condition is
> taken.
> 
> Changing the logic to be as it was before the problematic commit *and*
> only conditionally scheduling musb->irq_work resolves the regression:
> 
> $ ping 192.168.0.100
> ...
> 64 packets transmitted, 64 received, 0% packet loss, time 64475ms
> 
> Fixes: 92af4fc6ec33 ("usb: musb: Fix suspend with devices connected for a64")
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

> Cc: stable@vger.kernel.org
> ---
>  drivers/usb/musb/musb_core.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> index 8f09a387b773..4c8f0112481f 100644
> --- a/drivers/usb/musb/musb_core.c
> +++ b/drivers/usb/musb/musb_core.c
> @@ -2009,9 +2009,8 @@ static void musb_pm_runtime_check_session(struct musb *musb)
>  			schedule_delayed_work(&musb->irq_work,
>  					      msecs_to_jiffies(1000));
>  			musb->quirk_retries--;
> -			break;
>  		}
> -		fallthrough;
> +		break;
>  	case MUSB_QUIRK_B_INVALID_VBUS_91:
>  		if (musb->quirk_retries && !musb->flush_irq_work) {
>  			musb_dbg(musb,
> -- 
> 2.31.1
>
Tony Lindgren May 31, 2021, 11:40 a.m. UTC | #2
* Alexandre Belloni <alexandre.belloni@bootlin.com> [210528 15:35]:
> On 28/05/2021 16:04:46+0200, Thomas Petazzoni wrote:

> > In commit 92af4fc6ec33 ("usb: musb: Fix suspend with devices

> > connected for a64"), the logic to support the

> > MUSB_QUIRK_B_DISCONNECT_99 quirk was modified to only conditionally

> > schedule the musb->irq_work delayed work.

> > 

> > This commit badly breaks ECM Gadget on AM335X. Indeed, with this

> > commit, one can observe massive packet loss:

> > 

> > $ ping 192.168.0.100

> > ...

> > 15 packets transmitted, 3 received, 80% packet loss, time 14316ms

> > 

> > Reverting this commit brings back a properly functioning ECM

> > Gadget. An analysis of the commit seems to indicate that a mistake was

> > made: the previous code was not falling through into the

> > MUSB_QUIRK_B_INVALID_VBUS_91, but now it is, unless the condition is

> > taken.

> > 

> > Changing the logic to be as it was before the problematic commit *and*

> > only conditionally scheduling musb->irq_work resolves the regression:

> > 

> > $ ping 192.168.0.100

> > ...

> > 64 packets transmitted, 64 received, 0% packet loss, time 64475ms

> > 

> > Fixes: 92af4fc6ec33 ("usb: musb: Fix suspend with devices connected for a64")

> > Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

> Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>


Ouch, sorry about that one. And thanks for fixing it:

Acked-by: Tony Lindgren <tony@atomide.com>
Drew Fustini May 31, 2021, 5:28 p.m. UTC | #3
On Fri, May 28, 2021 at 04:04:46PM +0200, Thomas Petazzoni wrote:
> In commit 92af4fc6ec33 ("usb: musb: Fix suspend with devices

> connected for a64"), the logic to support the

> MUSB_QUIRK_B_DISCONNECT_99 quirk was modified to only conditionally

> schedule the musb->irq_work delayed work.

> 

> This commit badly breaks ECM Gadget on AM335X. Indeed, with this

> commit, one can observe massive packet loss:

> 

> $ ping 192.168.0.100

> ...

> 15 packets transmitted, 3 received, 80% packet loss, time 14316ms

> 

> Reverting this commit brings back a properly functioning ECM

> Gadget. An analysis of the commit seems to indicate that a mistake was

> made: the previous code was not falling through into the

> MUSB_QUIRK_B_INVALID_VBUS_91, but now it is, unless the condition is

> taken.

> 

> Changing the logic to be as it was before the problematic commit *and*

> only conditionally scheduling musb->irq_work resolves the regression:

> 

> $ ping 192.168.0.100

> ...

> 64 packets transmitted, 64 received, 0% packet loss, time 64475ms

> 

> Fixes: 92af4fc6ec33 ("usb: musb: Fix suspend with devices connected for a64")

> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

> Cc: stable@vger.kernel.org

> ---

>  drivers/usb/musb/musb_core.c | 3 +--

>  1 file changed, 1 insertion(+), 2 deletions(-)

> 

> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c

> index 8f09a387b773..4c8f0112481f 100644

> --- a/drivers/usb/musb/musb_core.c

> +++ b/drivers/usb/musb/musb_core.c

> @@ -2009,9 +2009,8 @@ static void musb_pm_runtime_check_session(struct musb *musb)

>  			schedule_delayed_work(&musb->irq_work,

>  					      msecs_to_jiffies(1000));

>  			musb->quirk_retries--;

> -			break;

>  		}

> -		fallthrough;

> +		break;

>  	case MUSB_QUIRK_B_INVALID_VBUS_91:

>  		if (musb->quirk_retries && !musb->flush_irq_work) {

>  			musb_dbg(musb,

> -- 

> 2.31.1


Tested-by: Drew Fustini <drew@beagleboard.org>


This patches fixes the problem on the BeagleBone Black (AM3358) where
the USB gadget interfaces would frequently reset. For example:

  configfs-gadget gadget: init rndis
  configfs-gadget gadget: RNDIS RX/TX early activation ...
  usb0: qlen 10
  configfs-gadget gadget: rndis_open
  rndis_set_param_medium: 0 4259840
  usb0: eth_start
  rndis_set_param_dev:
  configfs-gadget gadget: set_config: interface 2 (Mass Storage Function) requested delayed status
  configfs-gadget gadget: delayed_status count 1
  configfs-gadget gadget: reset ncm control 3
  configfs-gadget gadget: init ncm ctrl 3
  configfs-gadget gadget: notify speed 425984000
  configfs-gadget gadget: reset acm ttyGS0
  configfs-gadget gadget: activate acm ttyGS0
  configfs-gadget gadget: acm ttyGS0 serial state 0000
  configfs-gadget gadget: usb_composite_setup_continue
  configfs-gadget gadget: usb_composite_setup_continue: Completing delayed status
  configfs-gadget gadget: rndis req21.00 v0000 i0000 l24
  rndis_msg_parser: RNDIS_MSG_INIT
  configfs-gadget gadget: rndis reqa1.01 v0000 i0000 l1025
  configfs-gadget gadget: rndis req21.00 v0000 i0000 l32
  gen_ndis_query_resp: RNDIS_OID_GEN_PHYSICAL_MEDIUM
  configfs-gadget gadget: rndis reqa1.01 v0000 i0000 l1025
  configfs-gadget gadget: rndis req21.00 v0000 i0000 l76
  gen_ndis_query_resp: RNDIS_OID_802_3_PERMANENT_ADDRESS
  configfs-gadget gadget: rndis reqa1.01 v0000 i0000 l1025
  configfs-gadget gadget: rndis req21.00 v0000 i0000 l32
  gen_ndis_set_resp: RNDIS_OID_GEN_CURRENT_PACKET_FILTER 0000002d
  configfs-gadget gadget: rndis reqa1.01 v0000 i0000 l1025
  configfs-gadget gadget: init ncm
  configfs-gadget gadget: activate ncm
  usb1: qlen 10
  configfs-gadget gadget: ncm_open
  usb1: eth_start
  configfs-gadget gadget: reset ncm
  usb1: gether_disconnect
  configfs-gadget gadget: ncm reqa1.80 v0000 i0003 l28
  configfs-gadget gadget: non-CRC mode selected
  configfs-gadget gadget: ncm req21.8a v0000 i0003 l0
  configfs-gadget gadget: NCM16 selected
  configfs-gadget gadget: ncm req21.84 v0000 i0003 l0
  configfs-gadget gadget: init ncm
  configfs-gadget gadget: activate ncm
  usb1: qlen 10
  configfs-gadget gadget: ncm_open
  usb1: eth_start
  configfs-gadget gadget: acm ttyGS0 req21.20 v0000 i0005 l7
  configfs-gadget gadget: notify speed 425984000
  configfs-gadget gadget: notify connect true

I have posted dmesg log without the patch [1] where this happens often
and the dmesg log with the patch [2] where it does happen at all.

Thank you for fixing this!
Drew

[1] https://gist.github.com/pdp7/bd61e5f78545de182605992254d3eeee
[2] https://gist.github.com/pdp7/95b0f34fa1d423d4764984b400c562cf
diff mbox series

Patch

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 8f09a387b773..4c8f0112481f 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2009,9 +2009,8 @@  static void musb_pm_runtime_check_session(struct musb *musb)
 			schedule_delayed_work(&musb->irq_work,
 					      msecs_to_jiffies(1000));
 			musb->quirk_retries--;
-			break;
 		}
-		fallthrough;
+		break;
 	case MUSB_QUIRK_B_INVALID_VBUS_91:
 		if (musb->quirk_retries && !musb->flush_irq_work) {
 			musb_dbg(musb,