| Message ID | 20230208163418.342210-1-jassisinghbrar@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | usb: gadget: udc: max3420_udc: fix serialized access | expand |
On Wed, Feb 08, 2023 at 10:34:18AM -0600, jassisinghbrar@gmail.com wrote: > From: Jassi Brar <jaswinder.singh@linaro.org> > > The mutex 'spi_bus_mutex' should be used, instead of the spin-lock, > while changing the state of the kernel-thread. You forgot to say why this is the case. > Also changing the > usb-gadget state need not be protected by a spin-lock. Why not? Why isn't this a separate change? > This should fix the Smatch static checker warning > warn: sleeping in atomic context > > Fixes: 48ba02b2e2b1 ("usb: gadget: add udc driver for max3420") > Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org> > --- > drivers/usb/gadget/udc/max3420_udc.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) You forgot a "Reported-by:" line, right? And odd indentation in your changelog text. thanks, greg k-h
On Wed, Feb 08, 2023 at 10:34:18AM -0600, jassisinghbrar@gmail.com wrote:
> From: Jassi Brar <jaswinder.singh@linaro.org>
Also, housekeeping issue, I know Linaro has good email servers, please
use them and not gmail accounts to send patches so that we can validate
that you really are the correct author.
thanks,
greg k-h
On Wed, 8 Feb 2023 at 11:23, Greg KH <gregkh@linuxfoundation.org> wrote: > > On Wed, Feb 08, 2023 at 10:34:18AM -0600, jassisinghbrar@gmail.com wrote: > > From: Jassi Brar <jaswinder.singh@linaro.org> > > > > The mutex 'spi_bus_mutex' should be used, instead of the spin-lock, > > while changing the state of the kernel-thread. > > You forgot to say why this is the case. > It was 'inherited' (my fault) from drivers/usb/host/max3421-hcd.c which has the same issue. OK, I will also add to the log why that is a bad idea. > > Also changing the > > usb-gadget state need not be protected by a spin-lock. > > Why not? Why isn't this a separate change? > Because other low-level spi changes are protected by spin-lock and it seems ok to not to have to worry about such a race. I don't have the h/w anymore to actually test it, so it is just a patch from looking. I just got lazy to break it into two patches, will do that. > > This should fix the Smatch static checker warning > > warn: sleeping in atomic context > > > > Fixes: 48ba02b2e2b1 ("usb: gadget: add udc driver for max3420") > > Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org> > > --- > > drivers/usb/gadget/udc/max3420_udc.c | 10 ++++++---- > > 1 file changed, 6 insertions(+), 4 deletions(-) > > You forgot a "Reported-by:" line, right? > Yes, I forgot. thanks.
diff --git a/drivers/usb/gadget/udc/max3420_udc.c b/drivers/usb/gadget/udc/max3420_udc.c index ddf0ed3eb4f2..3666cc44f4e7 100644 --- a/drivers/usb/gadget/udc/max3420_udc.c +++ b/drivers/usb/gadget/udc/max3420_udc.c @@ -501,13 +501,16 @@ static irqreturn_t max3420_vbus_handler(int irq, void *dev_id) unsigned long flags; spin_lock_irqsave(&udc->lock, flags); + /* its a vbus change interrupt */ udc->vbus_active = !udc->vbus_active; udc->todo |= UDC_START; + + spin_unlock_irqrestore(&udc->lock, flags); + usb_udc_vbus_handler(&udc->gadget, udc->vbus_active); usb_gadget_set_state(&udc->gadget, udc->vbus_active ? USB_STATE_POWERED : USB_STATE_NOTATTACHED); - spin_unlock_irqrestore(&udc->lock, flags); if (udc->thread_task) wake_up_process(udc->thread_task); @@ -1298,15 +1301,14 @@ static int max3420_probe(struct spi_device *spi) static void max3420_remove(struct spi_device *spi) { struct max3420_udc *udc = spi_get_drvdata(spi); - unsigned long flags; usb_del_gadget_udc(&udc->gadget); - spin_lock_irqsave(&udc->lock, flags); + mutex_lock(&udc->spi_bus_mutex); kthread_stop(udc->thread_task); - spin_unlock_irqrestore(&udc->lock, flags); + mutex_unlock(&udc->spi_bus_mutex); } static const struct of_device_id max3420_udc_of_match[] = {