[Letux-kernel] [PATCH] usb3503: Fix reset polarity

David Shah dave at ds0.me
Sat Jul 25 16:11:47 CEST 2020


Hi Nikolaus,

Sorry, please ignore this patch for now, if not already merged.

The proper solution is to set GPIO_ACTIVE_LOW in the device tree, but
there are some other reliability issues with hub startup (the same
reason the modem sometimes took 255 seconds to appear on older
kernels).

Hopefully I will have an improved v2 patch soon :)

Best

David

On Thu, 2020-07-23 at 17:29 +0200, H. Nikolaus Schaller wrote:
> Hi Dave,
> 
> > Am 23.07.2020 um 16:31 schrieb David Shah <dave at ds0.me>:
> > 
> > It appears that the users of usb3503_reset expect state to be the
> > original active-low value.
> > 
> > Signed-off-by: David Shah <dave at ds0.me>
> > ---
> > drivers/usb/misc/usb3503.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/usb/misc/usb3503.c
> > b/drivers/usb/misc/usb3503.c
> > index e0c11331632a..9a228bc0566c 100644
> > --- a/drivers/usb/misc/usb3503.c
> > +++ b/drivers/usb/misc/usb3503.c
> > @@ -62,7 +62,7 @@ static int usb3503_reset(struct usb3503 *hub, int
> > state)
> > 		gpiod_set_value_cansleep(hub->connect, 0);
> > 
> > 	if (hub->reset)
> > -		gpiod_set_value_cansleep(hub->reset, !state);
> > +		gpiod_set_value_cansleep(hub->reset, state);
> 
> good finding!
> 
> Seems that it should have a
> 
> Fixes: 51d22e855ea3 ("usb: usb3503: Convert to use GPIO descriptors")
> 
> because it looks as if it was probably introduced there as a typo...
> 
> > 	/* Wait T_HUBINIT == 4ms for hub logic to stabilize */
> > 	if (state)
> > -- 
> > 2.27.0
> 
> I'll pick it to all branches that contain 51d22e855ea3
> 
> BR and thanks,
> Nikolaus
> 



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