Re: [PATCH 3/9] usb: dwc2/gadget: fix support for soft_connect udc framework feature

[Felipe Balbi]

Hi,

On Fri, Oct 17, 2014 at 10:44:35AM -0500, Felipe Balbi wrote:
> On Fri, Oct 17, 2014 at 12:43:48PM +0200, Marek Szyprowski wrote:
> > Hello,
> > 
> > On 2014-10-16 15:36, Felipe Balbi wrote:
> > >On Thu, Oct 16, 2014 at 02:57:59PM +0200, Marek Szyprowski wrote:
> > >>Enabling and disabling usb gadget by writing to
> > >>/sys/class/udc/*hsotg/soft_connect results in calling udc_start/udc_stop
> > >>functions with the same usb gadget driver, so the driver should not WARN
> > >>about such case.
> > >>
> > >>Signed-off-by: Marek Szyprowski <m.szyprow...@samsung.com>
> > >>---
> > >>  drivers/usb/dwc2/gadget.c | 2 +-
> > >>  1 file changed, 1 insertion(+), 1 deletion(-)
> > >>
> > >>diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> > >>index 8870e38c1d82..37fda4c03397 100644
> > >>--- a/drivers/usb/dwc2/gadget.c
> > >>+++ b/drivers/usb/dwc2/gadget.c
> > >>@@ -2892,7 +2892,7 @@ static int s3c_hsotg_udc_start(struct usb_gadget 
> > >>*gadget,
> > >>                  return -EINVAL;
> > >>          }
> > >>- WARN_ON(hsotg->driver);
> > >>+ WARN_ON(hsotg->driver && hsotg->driver != driver);
> > >the bug is in your ->udc_stop(). You should clear hsotg->driver to NULL
> > >there.
> > 
> > Ok, I will change udc_stop() to always zero hsotg->driver, like other udc
> > drivers. I was a bit confused by the fact that udc core passes driver to
> > udc_stop(), when called from soft_connect and NULL on gadget removal.
> 
> That can probably be cleaned up, I'll go have a look on all UDCs and
> make sure I won't break anything.

looks like chipidea is the only one still using that argument, if you
make your patch look like below:

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 7b5856f..ac14328 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -2934,8 +2934,7 @@ static int s3c_hsotg_udc_stop(struct usb_gadget *gadget,
 
        spin_lock_irqsave(&hsotg->lock, flags);
 
-       if (!driver)
-               hsotg->driver = NULL;
+       hsotg->driver = NULL;
 
        hsotg->gadget.speed = USB_SPEED_UNKNOWN;
 

I'll remove the argument.

-- 
balbi

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