dmaengine: usb-dmac: Make DMAC system sleep callbacks explicit

Commit Message

Yoshihiro Shimoda Jan. 17, 2019, 2:41 a.m. UTC

From: Phuong Nguyen <[e-mail]>

This commit fixes the issue that USB-DMAC hangs silently after system
resumes on R-Car Gen3 hence renesas_usbhs will not work correctly
when using USB-DMAC for bulk transfer e.g. ethernet or serial
gadgets.

The issue can be reproduced by these steps:
 1. modprobe g_serial
 2. Suspend and resume system.
 3. connect a usb cable to host side
 4. Transfer data from Host to Target
 5. cat /dev/ttyGS0 (Target side)
 6. echo "test" > /dev/ttyACM0 (Host side)

The 'cat' will not result anything. However, system still can work
normally.

Currently, USB-DMAC driver does not have system sleep callbacks hence
this driver relies on the PM core to force runtime suspend/resume to
suspend and reinitialize USB-DMAC during system resume. After
the commit 17218e0092f8 ("PM / genpd: Stop/start devices without
pm_runtime_force_suspend/resume()"), PM core will not force
runtime suspend/resume anymore so this issue happens.

To solve this, make system suspend resume explicit by using
pm_runtime_force_{suspend,resume}() as the system sleep callbacks.
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS()is used to make sure USB-DMAC suspended
after and initialized before renesas_usbhs."

Signed-off-by: Phuong Nguyen <[e-mail]>
Signed-off-by: Hiroyuki Yokoyama <[e-mail]>
Cc: <[e-mail]> # v4.16+
[shimoda: revise the commit log and add Cc tag]
Signed-off-by: Yoshihiro Shimoda <[e-mail]>
---
 drivers/dma/sh/usb-dmac.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Yoshihiro Shimoda Jan. 17, 2019, 2:51 a.m. UTC | #1

Hi Vinod (with correct email address),

I'm sorry, I should have checked your email address before I submitted...

Best regards,
Yoshihiro Shimoda

> From: Yoshihiro Shimoda, Sent: Thursday, January 17, 2019 11:42 AM
> 
> From: Phuong Nguyen <[e-mail]>
> 
> This commit fixes the issue that USB-DMAC hangs silently after system
> resumes on R-Car Gen3 hence renesas_usbhs will not work correctly
> when using USB-DMAC for bulk transfer e.g. ethernet or serial
> gadgets.
> 
> The issue can be reproduced by these steps:
>  1. modprobe g_serial
>  2. Suspend and resume system.
>  3. connect a usb cable to host side
>  4. Transfer data from Host to Target
>  5. cat /dev/ttyGS0 (Target side)
>  6. echo "test" > /dev/ttyACM0 (Host side)
> 
> The 'cat' will not result anything. However, system still can work
> normally.
> 
> Currently, USB-DMAC driver does not have system sleep callbacks hence
> this driver relies on the PM core to force runtime suspend/resume to
> suspend and reinitialize USB-DMAC during system resume. After
> the commit 17218e0092f8 ("PM / genpd: Stop/start devices without
> pm_runtime_force_suspend/resume()"), PM core will not force
> runtime suspend/resume anymore so this issue happens.
> 
> To solve this, make system suspend resume explicit by using
> pm_runtime_force_{suspend,resume}() as the system sleep callbacks.
> SET_NOIRQ_SYSTEM_SLEEP_PM_OPS()is used to make sure USB-DMAC suspended
> after and initialized before renesas_usbhs."
> 
> Signed-off-by: Phuong Nguyen <[e-mail]>
> Signed-off-by: Hiroyuki Yokoyama <[e-mail]>
> Cc: <[e-mail]> # v4.16+
> [shimoda: revise the commit log and add Cc tag]
> Signed-off-by: Yoshihiro Shimoda <[e-mail]>
> ---
>  drivers/dma/sh/usb-dmac.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
> index 7f7184c..59403f6 100644
> --- a/drivers/dma/sh/usb-dmac.c
> +++ b/drivers/dma/sh/usb-dmac.c
> @@ -694,6 +694,8 @@ static int usb_dmac_runtime_resume(struct device *dev)
>  #endif /* CONFIG_PM */
> 
>  static const struct dev_pm_ops usb_dmac_pm = {
> +	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> +				      pm_runtime_force_resume)
>  	SET_RUNTIME_PM_OPS(usb_dmac_runtime_suspend, usb_dmac_runtime_resume,
>  			   NULL)
>  };
> --
> 1.9.1

Sergei Shtylyov Jan. 17, 2019, 8:27 a.m. UTC | #2

On 17.01.2019 5:41, Yoshihiro Shimoda wrote:

> From: Phuong Nguyen <[e-mail]>
> 
> This commit fixes the issue that USB-DMAC hangs silently after system
> resumes on R-Car Gen3 hence renesas_usbhs will not work correctly
> when using USB-DMAC for bulk transfer e.g. ethernet or serial
> gadgets.
> 
> The issue can be reproduced by these steps:
>   1. modprobe g_serial
>   2. Suspend and resume system.
>   3. connect a usb cable to host side
>   4. Transfer data from Host to Target
>   5. cat /dev/ttyGS0 (Target side)
>   6. echo "test" > /dev/ttyACM0 (Host side)
> 
> The 'cat' will not result anything. However, system still can work
> normally.
> 
> Currently, USB-DMAC driver does not have system sleep callbacks hence
> this driver relies on the PM core to force runtime suspend/resume to
> suspend and reinitialize USB-DMAC during system resume. After
> the commit 17218e0092f8 ("PM / genpd: Stop/start devices without
> pm_runtime_force_suspend/resume()"), PM core will not force
> runtime suspend/resume anymore so this issue happens.
> 
> To solve this, make system suspend resume explicit by using
> pm_runtime_force_{suspend,resume}() as the system sleep callbacks.
> SET_NOIRQ_SYSTEM_SLEEP_PM_OPS()is used to make sure USB-DMAC suspended
                                  ^ space missing here

> after and initialized before renesas_usbhs."
> 
> Signed-off-by: Phuong Nguyen <[e-mail]>
> Signed-off-by: Hiroyuki Yokoyama <[e-mail]>
> Cc: <[e-mail]> # v4.16+
> [shimoda: revise the commit log and add Cc tag]
> Signed-off-by: Yoshihiro Shimoda <[e-mail]>
[...]

MBR, Sergei

Yoshihiro Shimoda Jan. 17, 2019, 8:44 a.m. UTC | #3

Hi Sergei,

> From: Sergei Shtylyov, Sent: Thursday, January 17, 2019 5:28 PM
> 
> On 17.01.2019 5:41, Yoshihiro Shimoda wrote:
<snip>
> > To solve this, make system suspend resume explicit by using
> > pm_runtime_force_{suspend,resume}() as the system sleep callbacks.
> > SET_NOIRQ_SYSTEM_SLEEP_PM_OPS()is used to make sure USB-DMAC suspended
>                                   ^ space missing here

Thank you for the pointed it out! I'll revise it on v2.

Best regards,
Yoshihiro Shimoda

Geert Uytterhoeven Jan. 17, 2019, 9:03 a.m. UTC | #4

Hi Shimoda-san,

CC linux-pm people

On Thu, Jan 17, 2019 at 9:48 AM Yoshihiro Shimoda
<[e-mail]> wrote:
> From: Phuong Nguyen <[e-mail]>
>
> This commit fixes the issue that USB-DMAC hangs silently after system
> resumes on R-Car Gen3 hence renesas_usbhs will not work correctly
> when using USB-DMAC for bulk transfer e.g. ethernet or serial
> gadgets.
>
> The issue can be reproduced by these steps:
>  1. modprobe g_serial
>  2. Suspend and resume system.
>  3. connect a usb cable to host side
>  4. Transfer data from Host to Target
>  5. cat /dev/ttyGS0 (Target side)
>  6. echo "test" > /dev/ttyACM0 (Host side)
>
> The 'cat' will not result anything. However, system still can work
> normally.
>
> Currently, USB-DMAC driver does not have system sleep callbacks hence
> this driver relies on the PM core to force runtime suspend/resume to
> suspend and reinitialize USB-DMAC during system resume. After
> the commit 17218e0092f8 ("PM / genpd: Stop/start devices without
> pm_runtime_force_suspend/resume()"), PM core will not force
> runtime suspend/resume anymore so this issue happens.
>
> To solve this, make system suspend resume explicit by using
> pm_runtime_force_{suspend,resume}() as the system sleep callbacks.
> SET_NOIRQ_SYSTEM_SLEEP_PM_OPS()is used to make sure USB-DMAC suspended
> after and initialized before renesas_usbhs."
>
> Signed-off-by: Phuong Nguyen <[e-mail]>
> Signed-off-by: Hiroyuki Yokoyama <[e-mail]>
> Cc: <[e-mail]> # v4.16+
> [shimoda: revise the commit log and add Cc tag]
> Signed-off-by: Yoshihiro Shimoda <[e-mail]>

Thanks for your patch!

This is similar in spirit to commits 1131b0a4af911de5 ("dmaengine:
rcar-dmac: Make DMAC reinit during system resume explicit") and
73dcc666d6bd0db5 ("dmaengine: rcar-dmac: Fix too early/late system
suspend/resume callbacks") for rcar-dmac.

I'm only wondering if the "late" variant would be sufficient here.
Does g_serial support wake-up?
Anyway, using the "noirq" variant, like you did, is probably the safest.

Reviewed-by: Geert Uytterhoeven <[e-mail]>

> ---
>  drivers/dma/sh/usb-dmac.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
> index 7f7184c..59403f6 100644
> --- a/drivers/dma/sh/usb-dmac.c
> +++ b/drivers/dma/sh/usb-dmac.c
> @@ -694,6 +694,8 @@ static int usb_dmac_runtime_resume(struct device *dev)
>  #endif /* CONFIG_PM */
>
>  static const struct dev_pm_ops usb_dmac_pm = {
> +       SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> +                                     pm_runtime_force_resume)
>         SET_RUNTIME_PM_OPS(usb_dmac_runtime_suspend, usb_dmac_runtime_resume,
>                            NULL)
>  };

Gr{oetje,eeting}s,

                        Geert

Yoshihiro Shimoda Jan. 17, 2019, 10:18 a.m. UTC | #5

Hi Geert-san,

> From: Geert Uytterhoeven, Sent: Thursday, January 17, 2019 6:03 PM
> 
> Hi Shimoda-san,
> 
> CC linux-pm people
<snip>
> 
> Thanks for your patch!
> 
> This is similar in spirit to commits 1131b0a4af911de5 ("dmaengine:
> rcar-dmac: Make DMAC reinit during system resume explicit") and
> 73dcc666d6bd0db5 ("dmaengine: rcar-dmac: Fix too early/late system
> suspend/resume callbacks") for rcar-dmac.
> 
> I'm only wondering if the "late" variant would be sufficient here.

I tried to use SET_LATE_... () instead of SET_NOIRQ_..., it also worked correctly.

> Does g_serial support wake-up?

I believe any USB gadgets don't support own system wake-up because they
are against USB host.

> Anyway, using the "noirq" variant, like you did, is probably the safest.
> 
> Reviewed-by: Geert Uytterhoeven <[e-mail]>

Thank you for your review!

Best regards,
Yoshihiro Shimoda

> > ---
> >  drivers/dma/sh/usb-dmac.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
> > index 7f7184c..59403f6 100644
> > --- a/drivers/dma/sh/usb-dmac.c
> > +++ b/drivers/dma/sh/usb-dmac.c
> > @@ -694,6 +694,8 @@ static int usb_dmac_runtime_resume(struct device *dev)
> >  #endif /* CONFIG_PM */
> >
> >  static const struct dev_pm_ops usb_dmac_pm = {
> > +       SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> > +                                     pm_runtime_force_resume)
> >         SET_RUNTIME_PM_OPS(usb_dmac_runtime_suspend, usb_dmac_runtime_resume,
> >                            NULL)
> >  };
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [e-mail]
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds

Patch

diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
index 7f7184c..59403f6 100644
--- a/drivers/dma/sh/usb-dmac.c
+++ b/drivers/dma/sh/usb-dmac.c
@@ -694,6 +694,8 @@  static int usb_dmac_runtime_resume(struct device *dev)
 #endif /* CONFIG_PM */
 
 static const struct dev_pm_ops usb_dmac_pm = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				      pm_runtime_force_resume)
 	SET_RUNTIME_PM_OPS(usb_dmac_runtime_suspend, usb_dmac_runtime_resume,
 			   NULL)
 };