Re: Mobility Radeon HD 4530/4570/545v: flicker in 1920x1080

[Alex Deucher]

On Wed, Nov 4, 2015 at 5:10 PM, Pavel Machek <pavel@xxxxxx> wrote:
> Hi!
>
>> >>>>index dac78ad..b86f06a 100644
>> >>>>--- a/drivers/gpu/drm/radeon/atombios_crtc.c
>> >>>>+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
>> >>>>@@ -569,6 +569,8 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
>> >>>>         radeon_crtc->pll_flags = 0;
>> >>>>
>> >>>>         if (ASIC_IS_AVIVO(rdev)) {
>> >>>>+               radeon_crtc->pll_flags |= RADEON_PLL_PREFER_MINM_OVER_MAXP;
>> >>>>+
>> >>>>                 if ((rdev->family == CHIP_RS600) ||
>> >>>>                     (rdev->family == CHIP_RS690) ||
>> >>>>                     (rdev->family == CHIP_RS740))
>> >>>>
>> >>>Help.. maybe... it is tricky to tell. It definitely does _not_ fix the
>> >>>issue completely.
>> >>You could also try the old pll algorithm:
>> >I reverted the patch above, and switched to the old algorithm.
>> >
>> >The flicker is still there. (But maybe its less horrible, like with
>> >RADEON_PLL_PREFER_MINM_OVER_MAXP).
>>
>> The flickering would vanish completely if that's the reason for the issue
>> you are seeing.
>
>> Try setting ref_div_min and ref_div_max to 2 in
>>  radeon_compute_pll_avivo().
>
> Ok, I did this, but no luck, still flickers. But the flicker only
> happens when something changes on screen, like dragging a big
> window. Is that consistent with wrong PLL timings?

Does it go away with radeon.dpm=0?  Sounds more like either memory
reclocking happening outside of vblank, or underflow to the display
controllers.

Alex

>
> diff --git a/config.32 b/config.32
> index 00e5dd2..4734158 100644
> --- a/config.32
> +++ b/config.32
> @@ -1090,7 +1090,7 @@ CONFIG_DEVTMPFS_MOUNT=y
>  CONFIG_PREVENT_FIRMWARE_BUILD=y
>  CONFIG_FW_LOADER=y
>  CONFIG_FIRMWARE_IN_KERNEL=y
> -CONFIG_EXTRA_FIRMWARE="radeon/R700_rlc.bin"
> +CONFIG_EXTRA_FIRMWARE="radeon/R700_rlc.bin radeon/RV710_smc.bin radeon/RV710_uvd.bin"
>  CONFIG_EXTRA_FIRMWARE_DIR="/lib/firmware"
>  # CONFIG_FW_LOADER_USER_HELPER_FALLBACK is not set
>  CONFIG_ALLOW_DEV_COREDUMP=y
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index dac78ad..dcc4f4d 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -569,6 +569,8 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
>         radeon_crtc->pll_flags = 0;
>
>         if (ASIC_IS_AVIVO(rdev)) {
> +               //radeon_crtc->pll_flags |= RADEON_PLL_PREFER_MINM_OVER_MAXP;
> +
>                 if ((rdev->family == CHIP_RS600) ||
>                     (rdev->family == CHIP_RS690) ||
>                     (rdev->family == CHIP_RS740))
> diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
> index 6743174..bebaf4f 100644
> --- a/drivers/gpu/drm/radeon/radeon_display.c
> +++ b/drivers/gpu/drm/radeon/radeon_display.c
> @@ -947,6 +947,7 @@ void radeon_compute_pll_avivo(struct radeon_pll *pll,
>         fb_div_max = pll->max_feedback_div;
>
>         if (pll->flags & RADEON_PLL_USE_FRAC_FB_DIV) {
> +               printk("radeon: fractional divider\n");
>                 fb_div_min *= 10;
>                 fb_div_max *= 10;
>         }
> @@ -966,6 +967,9 @@ void radeon_compute_pll_avivo(struct radeon_pll *pll,
>         else
>                 ref_div_max = pll->max_ref_div;
>
> +       ref_div_min = 2;
> +       ref_div_max = 2;
> +
>         /* determine allowed post divider range */
>         if (pll->flags & RADEON_PLL_USE_POST_DIV) {
>                 post_div_min = pll->post_div;
> @@ -1020,6 +1024,8 @@ void radeon_compute_pll_avivo(struct radeon_pll *pll,
>                 diff = abs(target_clock - (pll->reference_freq * fb_div) /
>                         (ref_div * post_div));
>
> +               printk("post_div = %d, diff = %d\n", post_div, diff);
> +
>                 if (diff < diff_best || (diff == diff_best &&
>                     !(pll->flags & RADEON_PLL_PREFER_MINM_OVER_MAXP))) {
>
> @@ -1028,6 +1034,7 @@ void radeon_compute_pll_avivo(struct radeon_pll *pll,
>                 }
>         }
>         post_div = post_div_best;
> +       printk("Selected post_div = %d\n", post_div);
>
>         /* get the feedback and reference divider for the optimal value */
>         avivo_get_fb_ref_div(nom, den, post_div, fb_div_max, ref_div_max,
> @@ -1062,7 +1069,7 @@ void radeon_compute_pll_avivo(struct radeon_pll *pll,
>         *ref_div_p = ref_div;
>         *post_div_p = post_div;
>
> -       DRM_DEBUG_KMS("%d - %d, pll dividers - fb: %d.%d ref: %d, post %d\n",
> +       printk("%d - %d, pll dividers - fb: %d.%d ref: %d, post %d\n",
>                       freq, *dot_clock_p * 10, *fb_div_p, *frac_fb_div_p,
>                       ref_div, post_div);
>  }
>
>
>> But I'm not 100% convinced that this is actually a PLL problem, try to
>> compile the firmware it complains about into the kernel as well.
>
> Did that, too.
>
> Best regards,
>                                                                         Pavel
> --
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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