[PATCH] usb: musb: remove extra check in musb_gadget_vbus_draw

[PATCH] usb: musb: remove extra check in musb_gadget_vbus_draw

[Ivaylo Dimitrov]

The check for musb->xceiv->set_power duplicates the check done in
usb_phy_set_power(). Moreover, not calling usb_phy_set_power() results in
current USB config max current not being propagated through usb_charger FW

Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
---
 drivers/usb/musb/musb_gadget.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index 6704a62..ba20272d 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -1628,8 +1628,6 @@ static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
 {
 	struct musb	*musb = gadget_to_musb(gadget);
 
-	if (!musb->xceiv->set_power)
-		return -EOPNOTSUPP;
 	return usb_phy_set_power(musb->xceiv, mA);
 }
 
-- 
1.9.1

Re: [PATCH] usb: musb: remove extra check in musb_gadget_vbus_draw

[Greg KH]

On Mon, Nov 14, 2022 at 10:59:47AM +0200, Ivaylo Dimitrov wrote:
> The check for musb->xceiv->set_power duplicates the check done in
> usb_phy_set_power(). Moreover, not calling usb_phy_set_power() results in
> current USB config max current not being propagated through usb_charger FW

What does "FW" mean here?

> 
> Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
> ---
>  drivers/usb/musb/musb_gadget.c | 2 --
>  1 file changed, 2 deletions(-)

And is this a bugfix?  If so, what commit id does it fix?  Should it go
to stable kernels?  What hardware was this tested on that this solved a
problem for?

Please fix this and send a v2.

thanks,

greg k-h

Re: [PATCH] usb: musb: remove extra check in musb_gadget_vbus_draw

[Tony Lindgren]

* Greg KH <gregkh@linuxfoundation.org> [221122 16:01]:
> On Mon, Nov 14, 2022 at 10:59:47AM +0200, Ivaylo Dimitrov wrote:
> > The check for musb->xceiv->set_power duplicates the check done in
> > usb_phy_set_power(). Moreover, not calling usb_phy_set_power() results in
> > current USB config max current not being propagated through usb_charger FW
> 
> What does "FW" mean here?
> 
> > 
> > Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
> > ---
> >  drivers/usb/musb/musb_gadget.c | 2 --
> >  1 file changed, 2 deletions(-)
> 
> And is this a bugfix?  If so, what commit id does it fix?  Should it go
> to stable kernels?  What hardware was this tested on that this solved a
> problem for?
> 
> Please fix this and send a v2.

Ivaylo please also test with the musb phy changes in Linux next that might
affect this patch.

Regards,

Tony

[PATCH v2] usb: musb: remove extra check in musb_gadget_vbus_draw

[Ivaylo Dimitrov]

The checks for musb->xceiv and musb->xceiv->set_power duplicate those in
usb_phy_set_power(), so there is no need of them. Moreover, not calling
usb_phy_set_power() results in usb_phy_set_charger_current() not being
called, so current USB config max current is not propagated through USB
charger framework and charger drivers may try to draw more current than
allowed or possible.

Fix that by removing those extra checks and calling usb_phy_set_power()
directly.

Tested on Motorola Droid4 and Nokia N900

Fixes: a9081a008f84 ("usb: phy: Add USB charger support")
Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
---
 drivers/usb/musb/musb_gadget.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index 6cb9514..31c4432 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -1630,8 +1630,6 @@ static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
 {
 	struct musb	*musb = gadget_to_musb(gadget);
 
-	if (!musb->xceiv || !musb->xceiv->set_power)
-		return -EOPNOTSUPP;
 	return usb_phy_set_power(musb->xceiv, mA);
 }
 
-- 
1.9.1