[PATCH] drm/radeon: fix PLL sharing on DCE6.1

[Alex Deucher]

On Thu, May 5, 2016 at 5:02 AM, Lucas Stach <dev at lynxeye.de> wrote:
> On DCE6.1 PPLL2 is exclusively available to UNIPHYA, so it should not
> be taken into consideration when looking for an already enabled PLL
> to be shared with other outputs.
>
> This fixes the broken VGA port (TRAVIS DP->VGA bridge) on my Richland
> based laptop, where the internal display is connected to UNIPHYA through
> a TRAVIS DP->LVDS bridge.
>
> Bug:
> https://bugs.freedesktop.org/show_bug.cgi?id=78987
>
> Signed-off-by: Lucas Stach <dev at lynxeye.de>

Nice catch.  Need to add a check for the non-dp case as well I think.
How about the attached patch?

Alex

> ---
>  drivers/gpu/drm/radeon/atombios_crtc.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index b80b08f..401bcbd 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -1739,7 +1739,8 @@ static u32 radeon_get_pll_use_mask(struct drm_crtc *crtc)
>   * also in DP mode.  For DP, a single PPLL can be used for all DP
>   * crtcs/encoders.
>   */
> -static int radeon_get_shared_dp_ppll(struct drm_crtc *crtc)
> +static int radeon_get_shared_dp_ppll(struct radeon_device *rdev,
> +                                    struct drm_crtc *crtc)
>  {
>         struct drm_device *dev = crtc->dev;
>         struct drm_crtc *test_crtc;
> @@ -1751,6 +1752,10 @@ static int radeon_get_shared_dp_ppll(struct drm_crtc *crtc)
>                 test_radeon_crtc = to_radeon_crtc(test_crtc);
>                 if (test_radeon_crtc->encoder &&
>                     ENCODER_MODE_IS_DP(atombios_get_encoder_mode(test_radeon_crtc->encoder))) {
> +                       /* PPLL2 is exclusive to UNIPHYA on DCE61 */
> +                       if (ASIC_IS_DCE61(rdev) && !ASIC_IS_DCE8(rdev) &&
> +                           test_radeon_crtc->pll_id == ATOM_PPLL2)
> +                               continue;
>                         /* for DP use the same PLL for all */
>                         if (test_radeon_crtc->pll_id != ATOM_PPLL_INVALID)
>                                 return test_radeon_crtc->pll_id;
> @@ -1859,7 +1864,7 @@ static int radeon_atom_pick_pll(struct drm_crtc *crtc)
>                                 return ATOM_PPLL_INVALID;
>                         else {
>                                 /* use the same PPLL for all DP monitors */
> -                               pll = radeon_get_shared_dp_ppll(crtc);
> +                               pll = radeon_get_shared_dp_ppll(rdev, crtc);
>                                 if (pll != ATOM_PPLL_INVALID)
>                                         return pll;
>                         }
> @@ -1907,7 +1912,7 @@ static int radeon_atom_pick_pll(struct drm_crtc *crtc)
>                                 return ATOM_PPLL_INVALID;
>                         else {
>                                 /* use the same PPLL for all DP monitors */
> -                               pll = radeon_get_shared_dp_ppll(crtc);
> +                               pll = radeon_get_shared_dp_ppll(rdev, crtc);
>                                 if (pll != ATOM_PPLL_INVALID)
>                                         return pll;
>                         }
> @@ -1962,7 +1967,7 @@ static int radeon_atom_pick_pll(struct drm_crtc *crtc)
>                                 return ATOM_DCPLL;
>                         else {
>                                 /* use the same PPLL for all DP monitors */
> -                               pll = radeon_get_shared_dp_ppll(crtc);
> +                               pll = radeon_get_shared_dp_ppll(rdev, crtc);
>                                 if (pll != ATOM_PPLL_INVALID)
>                                         return pll;
>                         }
> --
> 2.5.5
>
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
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