linux-kernel - Re: [PATCH] DRM: UDL: get rid of useless vblank initialization

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Date:   Tue, 23 Oct 2018 11:01:14 +0000
From:   Eugeniy Paltsev <eugeniy.paltsev@...opsys.com>
To:     "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
        "airlied@...ux.ie" <airlied@...ux.ie>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "daniel.vetter@...ll.ch" <daniel.vetter@...ll.ch>,
        "linux-snps-arc@...ts.infradead.org" 
        <linux-snps-arc@...ts.infradead.org>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>,
        "marcheu@...omium.org" <marcheu@...omium.org>,
        Alexey Brodkin <alexey.brodkin@...opsys.com>,
        "maarten.lankhorst@...ux.intel.com" 
        <maarten.lankhorst@...ux.intel.com>,
        "gustavo@...ovan.org" <gustavo@...ovan.org>,
        "sean@...rly.run" <sean@...rly.run>
Subject: Re: [PATCH] DRM: UDL: get rid of useless vblank initialization

Hi David,

Maybe you have any comments or remarks about this patch?
And if you don't could you please apply it. Thanks!

On Fri, 2018-09-28 at 17:41 +0300, Eugeniy Paltsev wrote:
> UDL doesn't support vblank functionality so we don't need to
> initialize vblank here (we are able to send page flip
> completion events even without vblank initialization)
> 
> Moreover current drm_vblank_init call with num_crtcs > 0 causes
> sending DRM_EVENT_FLIP_COMPLETE event with zero timestamp every
> time. This breaks userspace apps (for example weston) which
> relies on timestamp value.
> 
> Reviewed-by: Daniel Vetter <daniel.vetter@...ll.ch>
> Cc: stable@...r.kernel.org
> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@...opsys.com>
> ---
>  drivers/gpu/drm/udl/udl_main.c | 7 +------
>  1 file changed, 1 insertion(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
> index f455f095a146..1b014d92855b 100644
> --- a/drivers/gpu/drm/udl/udl_main.c
> +++ b/drivers/gpu/drm/udl/udl_main.c
> @@ -350,15 +350,10 @@ int udl_driver_load(struct drm_device *dev, unsigned long flags)
>  	if (ret)
>  		goto err;
>  
> -	ret = drm_vblank_init(dev, 1);
> -	if (ret)
> -		goto err_fb;
> -
>  	drm_kms_helper_poll_init(dev);
>  
>  	return 0;
> -err_fb:
> -	udl_fbdev_cleanup(dev);
> +
>  err:
>  	if (udl->urbs.count)
>  		udl_free_urb_list(dev);
-- 
 Eugeniy Paltsev