[PATCHv3 29/30] drm/omap: use drm_atomic_helper_shutdown()

[Laurent Pinchart]

Hi Tomi,

On Wednesday 29 Mar 2017 12:08:19 Tomi Valkeinen wrote:
> On 29/03/17 11:49, Laurent Pinchart wrote:
> > On Tuesday 28 Mar 2017 16:08:15 Tomi Valkeinen wrote:
> >> Use drm_atomic_helper_shutdown() to ensure that all crtcs are disabled
> >> when unloading the driver.
> >> 
> >> Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ti.com>
> >> Cc: Daniel Vetter <daniel at ffwll.ch>
> >> 
> >> ---
> >> 
> >>  drivers/gpu/drm/omapdrm/omap_drv.c | 2 ++
> >>  1 file changed, 2 insertions(+)
> >> 
> >> diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c
> >> b/drivers/gpu/drm/omapdrm/omap_drv.c index ad8d16cf819c..7b917c0c1a27
> >> 100644
> >> --- a/drivers/gpu/drm/omapdrm/omap_drv.c
> >> +++ b/drivers/gpu/drm/omapdrm/omap_drv.c
> >> @@ -865,6 +865,8 @@ static int pdev_remove(struct platform_device *pdev)
> >> 
> >>  	if (priv->fbdev)
> >>  	
> >>  		omap_fbdev_free(ddev);
> >> 
> >> +	drm_atomic_helper_shutdown(ddev);
> >> +
> > 
> > Can the hardware still be enabled at this point ? If pdev_remove() is
> > called we shouldn't have any application holding the device open
> > (otherwise we'll crash miserably), and the fbdev compatibility layer is
> > disabled on the previous line.
> 
> The hw is disabled before drm_atomic_helper_shutdown() is called only if
> you have fbdev. And fbdev on all the connectors. If that's not the case,
> we need drm_atomic_helper_shutdown() to disable the hw.

But if you have no fbdev, as userspace must not hold the device node open 
here, isn't the device disabled already ?

-- 
Regards,

Laurent Pinchart