On 2017-07-05 08:21, Daniel Vetter wrote:
> On Tue, Jul 04, 2017 at 12:37:01PM +0200, Peter Rosin wrote:
>> This makes the redundant fb helpers .load_lut, .gamma_set and .gamma_get
>> completely obsolete.
>>
>> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
>> ---
>> drivers/gpu/drm/drm_fb_helper.c | 165 +++++++++++++++++++++++-----------------
>> 1 file changed, 94 insertions(+), 71 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
>> index b75b1f2..7f8199a 100644
>> --- a/drivers/gpu/drm/drm_fb_helper.c
>> +++ b/drivers/gpu/drm/drm_fb_helper.c
>> @@ -1257,27 +1257,6 @@ void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
>> }
>> EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
>>
>> -static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
>> - u16 blue, u16 regno, struct fb_info *info)
>> -{
>> - struct drm_fb_helper *fb_helper = info->par;
>> - struct drm_framebuffer *fb = fb_helper->fb;
>> -
>> - /*
>> - * The driver really shouldn't advertise pseudo/directcolor
>> - * visuals if it can't deal with the palette.
>> - */
>> - if (WARN_ON(!fb_helper->funcs->gamma_set ||
>> - !fb_helper->funcs->gamma_get))
>> - return -EINVAL;
>> -
>> - WARN_ON(fb->format->cpp[0] != 1);
>> -
>> - fb_helper->funcs->gamma_set(crtc, red, green, blue, regno);
>> -
>> - return 0;
>> -}
>> -
>> static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
>> {
>> u32 *palette = (u32 *)info->pseudo_palette;
>> @@ -1310,54 +1289,68 @@ static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
>> return 0;
>> }
>>
>> -/**
>> - * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
>> - * @cmap: cmap to set
>> - * @info: fbdev registered by the helper
>> - */
>> -int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
>> +static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info)
>> {
>> struct drm_fb_helper *fb_helper = info->par;
>> - struct drm_device *dev = fb_helper->dev;
>> - const struct drm_crtc_helper_funcs *crtc_funcs;
>> - u16 *red, *green, *blue, *transp;
>> struct drm_crtc *crtc;
>> u16 *r, *g, *b;
>> - int i, j, rc = 0;
>> - int start;
>> + int i, ret = 0;
>>
>> - if (oops_in_progress)
>> - return -EBUSY;
>> + for (i = 0; i < fb_helper->crtc_count; i++) {
>> + crtc = fb_helper->crtc_info[i].mode_set.crtc;
>> + if (!crtc->funcs->gamma_set || !crtc->gamma_size)
>> + return -EINVAL;
>>
>> - mutex_lock(&fb_helper->lock);
>> - if (!drm_fb_helper_is_bound(fb_helper)) {
>> - mutex_unlock(&fb_helper->lock);
>> - return -EBUSY;
>> - }
>> + if (cmap->start + cmap->len > crtc->gamma_size)
>> + return -EINVAL;
>>
>> - drm_modeset_lock_all(dev);
>> - if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
>> - rc = setcmap_pseudo_palette(cmap, info);
>> - goto out;
>> + r = crtc->gamma_store;
>> + g = r + crtc->gamma_size;
>> + b = g + crtc->gamma_size;
>> +
>> + memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
>> + memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
>> + memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
>> +
>> + ret = crtc->funcs->gamma_set(crtc, r, g, b,
>> + crtc->gamma_size, NULL);
>> + if (ret)
>> + return ret;
>> }
>>
>> - for (i = 0; i < fb_helper->crtc_count; i++) {
>> - crtc = fb_helper->crtc_info[i].mode_set.crtc;
>> - crtc_funcs = crtc->helper_private;
>> + return ret;
>> +}
>
> For the legacy path you need to keep the drm_modeset_lock_all (but only in
> setcmap_legacy). Otherwise this part here looks good.
Oops, didn't intend to zap that one. Thanks for catching!
>>
>> - red = cmap->red;
>> - green = cmap->green;
>> - blue = cmap->blue;
>> - transp = cmap->transp;
>> - start = cmap->start;
>> +static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
>> +{
>> + struct drm_fb_helper *fb_helper = info->par;
>> + struct drm_device *dev = fb_helper->dev;
>> + struct drm_modeset_acquire_ctx ctx;
>> + struct drm_crtc_state *crtc_state;
>> + struct drm_atomic_state *state;
>> + struct drm_crtc *crtc;
>> + u16 *r, *g, *b;
>> + int i, ret = 0;
>>
>> - if (!crtc->gamma_size) {
>> - rc = -EINVAL;
>> + state = drm_atomic_state_alloc(dev);
>> + if (!state)
>> + return -ENOMEM;
>> + drm_modeset_acquire_init(&ctx, 0);
>> +retry:
>> + ret = drm_modeset_lock_all_ctx(dev, &ctx);
>
> With atomic you don't need to grab locks, this is done behind the scenes
> (as long as you handle the retry/backoff correctly). See the kerneldoc for
> the various drm_atomic_get_*_state functions.
It doesn't work if I remove it. What is the disconnect?
>> + if (ret)
>> + goto fini;
>> + state->acquire_ctx = &ctx;
>> + for (i = 0; i < fb_helper->crtc_count; i++) {
>> + crtc = fb_helper->crtc_info[i].mode_set.crtc;
>> + if (!crtc->funcs->gamma_set) {
>> + ret = -EINVAL;
>> goto out;
>> }
>>
>> - if (cmap->start + cmap->len > crtc->gamma_size) {
>> - rc = -EINVAL;
>> + crtc_state = drm_atomic_get_crtc_state(state, crtc);
>> + if (IS_ERR(crtc_state)) {
>> + ret = PTR_ERR(crtc_state);
>> goto out;
>> }
>>
>> @@ -1369,27 +1362,57 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
>> memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
>> memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
>>
>> - for (j = 0; j < cmap->len; j++) {
>> - u16 hred, hgreen, hblue, htransp = 0xffff;
>> + ret = crtc->funcs->gamma_set(crtc, r, g, b,
>> + crtc->gamma_size, crtc_state);
>
> I guess my description of what I have in mind wasn't really clear. I think
> a proper atomic commit should never reuse one of the old hooks
> (->gamma_set) here, that's just confusing. Instead what I had in mind is
> to do the proper adjusting that gamma_set does here in this function, i.e.
>
> - create the new blob, fill it with the cmap data
>
> - assign that blob to the crtc state:
>
> drm_atomic_replace_property_blob(&crtc_state->gamma_lut,
> new_table, &temp);
That function is static, and...
> Note that the drm_atomic_helper_legacy_gamma_set() does that in the most
> convoluted way by going through a few layers.
>
> - The one thing you need to do on top is check that the gamma_lut property
> is supported (just check whether dev->mode_config.gamma_lut_property
> exists). That check is instead of checking for ->gamma_set.
...drm_atomic_helper_legacy_gamma_set calls drm_atomic_crtc_set_property
which is already exported and performs all the checks I can think of...
> Checking for matching size is optional, the driver must do that already
> (for the atomic property).
...except this one.
> This way your previous patch isn't needed, and we don't need to change all
> the legacy callbacks. The only downside is that we duplicate a bit of the
> atomic commit setup scaffolding, but that's imo ok. You could extract that
> into a helper function shared between this code here and
> drm_atomic_helper_legacy_gamma_set(), but that seems frankly overkill to
> me. Creating atomic commits in the kernel is simply a bit verbose, but the
> benefit of the current framework is that the driver side looks a lot
> simpler.
But, yup, ditching 4/16 feels very nice. I'll mimic the code in
drm_atomic_helper_legacy_gamma_set for the v4 version of setcmap_atomic.
Good suggestion, and thanks for the more verbose explanation.
>> + if (ret)
>> + goto out;
>> + }
>>
>> - hred = *red++;
>> - hgreen = *green++;
>> - hblue = *blue++;
>> + ret = drm_atomic_commit(state);
>> + if (ret == -EDEADLK) {
>> + drm_modeset_backoff(&ctx);
>> + goto retry;
>> + }
>>
>> - if (transp)
>> - htransp = *transp++;
>> +out:
>> + drm_modeset_drop_locks(&ctx);
>> +fini:
>> + drm_modeset_acquire_fini(&ctx);
>> + drm_atomic_state_put(state);
>>
>> - rc = setcolreg(crtc, hred, hgreen, hblue, start++, info);
>> - if (rc)
>> - goto out;
>> - }
>> - if (crtc_funcs->load_lut)
>> - crtc_funcs->load_lut(crtc);
>> + return ret;
>> +}
>> +
>> +/**
>> + * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
>> + * @cmap: cmap to set
>> + * @info: fbdev registered by the helper
>> + */
>> +int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
>> +{
>> + struct drm_fb_helper *fb_helper = info->par;
>> + int ret;
>> +
>> + if (oops_in_progress)
>> + return -EBUSY;
>> +
>> + mutex_lock(&fb_helper->lock);
>> +
>> + if (!drm_fb_helper_is_bound(fb_helper)) {
>> + mutex_unlock(&fb_helper->lock);
>> + return -EBUSY;
>> }
>> - out:
>> - drm_modeset_unlock_all(dev);
>> +
>> + if (info->fix.visual == FB_VISUAL_TRUECOLOR)
>> + ret = setcmap_pseudo_palette(cmap, info);
>> + else if (drm_drv_uses_atomic_modeset(fb_helper->dev))
>> + ret = setcmap_atomic(cmap, info);
>> + else
>> + ret = setcmap_legacy(cmap, info);
>> +
>> mutex_unlock(&fb_helper->lock);
>> - return rc;
>> +
>> + return ret;
>> }
>> EXPORT_SYMBOL(drm_fb_helper_setcmap);
>
> Besides the 2 comments this looks good and will get my r-b once revised.
>
> Also on patches 1-3:
>
> Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Excellent!
Cheers,
peda
> Cheers, Daniel
>>
>> --
>> 2.1.4
>>
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>
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