linux-kernel - Re: [PATCH v2 1/8] drm/rect: Add some drm_clip

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Message-ID: <571F96C7.1060800@tronnes.org>
Date:	Tue, 26 Apr 2016 18:26:47 +0200
From:	Noralf Trønnes <noralf@...nnes.org>
To:	Laurent Pinchart <laurent.pinchart@...asonboard.com>
Cc:	Ville Syrjälä <ville.syrjala@...ux.intel.com>,
	linux-fbdev@...r.kernel.org, tomi.valkeinen@...com,
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/8] drm/rect: Add some drm_clip_rect utility functions


Den 25.04.2016 23:13, skrev Laurent Pinchart:
> Hi Noralf,
>
> On Monday 25 Apr 2016 20:35:18 Noralf Trønnes wrote:
>> Den 25.04.2016 18:38, skrev Ville Syrjälä:
>>> On Mon, Apr 25, 2016 at 06:05:20PM +0200, Daniel Vetter wrote:
>>>> On Mon, Apr 25, 2016 at 06:09:44PM +0300, Ville Syrjälä wrote:
>>>>> On Mon, Apr 25, 2016 at 04:03:13PM +0200, Noralf Trønnes wrote:
>>>>>> Den 25.04.2016 15:02, skrev Ville Syrjälä:
>>>>>>> On Mon, Apr 25, 2016 at 02:55:52PM +0200, Noralf Trønnes wrote:
>>>>>>>> Den 25.04.2016 14:39, skrev Ville Syrjälä:
>>>>>>>>> On Sun, Apr 24, 2016 at 10:48:55PM +0200, Noralf Trønnes wrote:
>>>>>>>>>> Add some utility functions for struct drm_clip_rect.

[...]

>> How about we just drop this patch?
>> I couldn't find anyone else that merge these clips, they just loop and
>> handle them individually.
>>
>> The relevant part in drm_fb_helper would become:
>>
>> static void drm_fb_helper_dirty_work(struct work_struct *work)
>> {
>>       struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
>> dirty_work);
>>       struct drm_clip_rect *clip = &helper->dirty_clip;
>>       struct drm_clip_rect clip_copy;
>>       unsigned long flags;
>>
>>       spin_lock_irqsave(&helper->dirty_lock, flags);
>>       clip_copy = *clip;
>>       clip->x1 = clip->y1 = ~0;
>>       clip->x2 = clip->y2 = 0;
>>       spin_unlock_irqrestore(&helper->dirty_lock, flags);
>>
>>       helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
>> }
>>
>> static void drm_fb_helper_dirty_init(struct drm_fb_helper *helper)
>> {
>>       spin_lock_init(&helper->dirty_lock);
>>       INIT_WORK(&helper->dirty_work, drm_fb_helper_dirty_work);
>>       helper->dirty_clip.x1 = helper->dirty_clip.y1 = ~0;
>> }
>>
>> static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y,
>>                   u32 width, u32 height)
>> {
>>       struct drm_fb_helper *helper = info->par;
>>       struct drm_clip_rect *clip = &helper->dirty_clip;
>>       unsigned long flags;
>>
>>       if (!helper->fb->funcs->dirty)
>>           return;
>>
>>       spin_lock_irqsave(&helper->dirty_lock, flags);
>>       clip->x1 = min(clip->x1, x);
>>       clip->y1 = min(clip->y1, y);
>>       clip->x2 = max(clip->x2, x + width);
>>       clip->y2 = max(clip->y2, y + height);
>>       spin_unlock_irqrestore(&helper->dirty_lock, flags);
>>
>>       schedule_work(&helper->dirty_work);
>> }
>>
>>
>> And the driver would use this tinydrm function:
>>
>> void tinydrm_merge_clips(struct drm_clip_rect *dst,
>>                struct drm_clip_rect *src, unsigned num_clips,
>>                unsigned flags, u32 width, u32 height)
>> {
>>       int i;
> Nitpicking here, as i never takes negative values, could you make it an
> unsigned int ?

Sure.

>>       if (!src || !num_clips) {
>>           dst->x1 = 0;
>>           dst->x2 = width;
>>           dst->y1 = 0;
>>           dst->y2 = height;
>>           return;
>>       }
>>
>>       dst->x1 = dst->y1 = ~0;
>>       dst->x2 = dst->y2 = 0;
>>
>>       for (i = 0; i < num_clips; i++) {
>>           if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY)
>>               i++;
>>           dst->x1 = min(dst->x1, src[i].x1);
>>           dst->x2 = max(dst->x2, src[i].x2);
>>           dst->y1 = min(dst->y1, src[i].y1);
>>           dst->y2 = max(dst->y2, src[i].y2);
>>       }
>>
>>       if (dst->x2 > width || dst->y2 > height ||
>>           dst->x1 >= dst->x2 || dst->y1 >= dst->y2) {
>>           DRM_DEBUG_KMS("Illegal clip: x1=%u, x2=%u, y1=%u, y2=%u\n",
>>                     dst->x1, dst->x2, dst->y1, dst->y2);
>>           dst->x1 = dst->y1 = 0;
>>           dst->x2 = width;
>>           dst->y2 = height;
>>       }
>> }
>>
>> static int mipi_dbi_dirtyfb(struct drm_framebuffer *fb, void *vmem,
>>                   unsigned flags, unsigned color,
>>                   struct drm_clip_rect *clips, unsigned num_clips)
>> {
>>       struct drm_clip_rect clip;
>>
>>       tinydrm_merge_clips(&clip, clips, num_clips, flags,
>>                   fb->width, fb->height);