[PATCH v2 1/5] usb: dwc3: Add Keystone specific glue layer

[Paul Zimmerman]

> From: linux-usb-owner at vger.kernel.org [mailto:linux-usb-owner at vger.kernel.org] On Behalf Of Santosh Shilimkar
> Sent: Friday, December 06, 2013 1:40 PM
> 
> On Friday 06 December 2013 03:28 PM, Felipe Balbi wrote:
> > Hi,
> >
> > On Wed, Dec 04, 2013 at 03:10:07PM -0500, WingMan Kwok wrote:
> >> Add Keystone platform specific glue layer to support
> >> USB3 Host mode.
> >>
> >> Cc: Santosh Shilimkar <santosh.shilimkar at ti.com>
> >> Cc: Felipe Balbi <balbi at ti.com>
> >> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> >> Signed-off-by: WingMan Kwok <w-kwok2 at ti.com>
> >> ---
> >>  drivers/usb/dwc3/Kconfig         |    7 ++
> >>  drivers/usb/dwc3/Makefile        |    1 +
> >>  drivers/usb/dwc3/dwc3-keystone.c |  210 ++++++++++++++++++++++++++++++++++++++
> >>  3 files changed, 218 insertions(+)
> >>  create mode 100644 drivers/usb/dwc3/dwc3-keystone.c
> 
> [..]
> 
> >> +static irqreturn_t dwc3_keystone_interrupt(int irq, void *_kdwc)
> >> +{
> >> +	struct dwc3_keystone	*kdwc = _kdwc;
> >> +
> >> +	spin_lock(&kdwc->lock);
> >
> > Isn't this lock unnecessary ? This handler will run with IRQs disabled
> > anyway.
> >
> Indeed.

Say what? AFAIK it's necessary to take the driver lock inside the interrupt
handler, because of SMP. Here is the equivalent routine from dwc3-omap.c:

static irqreturn_t dwc3_omap_interrupt(int irq, void *_omap)
{
        struct dwc3_omap        *omap = _omap;
        u32                     reg;

        spin_lock(&omap->lock);

        ...
}

Has this now become unnecessary?

-- 
Paul