On Fri, Feb 17, 2017 at 11:22:07AM -0200, Paulo Zanoni wrote: > Possible problems of the current if-ladder: > - It's a huge if ladder with almost a different check for each of > our platforms. > - It mixes 3 different types of checks: IS_GENX, IS_PLATFORM and > IS_GROUP_OF_PLATFORMS. > - As demonstrated by the recent IS_G4X commit, it's not easy to be > sure if a platform down on the list isn't also checked earlier. > - As demonstrated by the WARN at the end, it's not easy to be sure > if we're actually checking for every single platform. > > Possible advantages of the new switch statement: > - It may be easier for the compiler to optimize stuff (I didn't > check this), especially since the values are labels of an enum. > - The compiler will tell us in case we miss some platform. > - All platforms are explicitly there instead of maybe hidden in some > check for a certain group of platforms such as IS_GEN9_BC.
Performance is a bit of a moot point since this is run exaclty once, but the IS_GEN9_BC() stuff I tend to agree with. I don't really like those macros at all since they don't actully mean anything as far as the hardware features go. > > Possible disadvantages with the new code: > - A few lines bigger. > > Signed-off-by: Paulo Zanoni <[email protected]> > --- > drivers/gpu/drm/i915/intel_cdclk.c | 103 > ++++++++++++++++++++++--------------- > 1 file changed, 62 insertions(+), 41 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_cdclk.c > b/drivers/gpu/drm/i915/intel_cdclk.c > index 7c92dc7..58a2f5c 100644 > --- a/drivers/gpu/drm/i915/intel_cdclk.c > +++ b/drivers/gpu/drm/i915/intel_cdclk.c > @@ -1789,49 +1789,70 @@ void intel_init_cdclk_hooks(struct drm_i915_private > *dev_priv) > dev_priv->display.modeset_calc_cdclk = skl_modeset_calc_cdclk; > } > > - if (IS_GEN9_BC(dev_priv)) > - dev_priv->display.get_cdclk = skl_get_cdclk; > - else if (IS_GEN9_LP(dev_priv)) > - dev_priv->display.get_cdclk = bxt_get_cdclk; > - else if (IS_BROADWELL(dev_priv)) > - dev_priv->display.get_cdclk = bdw_get_cdclk; > - else if (IS_HASWELL(dev_priv)) > - dev_priv->display.get_cdclk = hsw_get_cdclk; > - else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) > - dev_priv->display.get_cdclk = vlv_get_cdclk; > - else if (IS_GEN6(dev_priv) || IS_IVYBRIDGE(dev_priv)) > + switch (INTEL_INFO(dev_priv)->platform) { > + case INTEL_PLATFORM_UNINITIALIZED: Just default: ? > + MISSING_CASE(INTEL_INFO(dev_priv)->platform); > + /* Fall through. */ > + case INTEL_I830: > + dev_priv->display.get_cdclk = fixed_133mhz_get_cdclk; > + break; > + case INTEL_I845G: > + dev_priv->display.get_cdclk = fixed_200mhz_get_cdclk; > + break; > + case INTEL_I85X: > + dev_priv->display.get_cdclk = i85x_get_cdclk; > + break; > + case INTEL_I865G: > + dev_priv->display.get_cdclk = fixed_266mhz_get_cdclk; > + break; > + case INTEL_I915G: > + dev_priv->display.get_cdclk = fixed_333mhz_get_cdclk; > + break; > + case INTEL_I915GM: > + dev_priv->display.get_cdclk = i915gm_get_cdclk; > + break; > + case INTEL_I945G: > + case INTEL_I965G: > + case INTEL_SANDYBRIDGE: > + case INTEL_IVYBRIDGE: I don't particularly like this disorder. I just managed to get the list into some sort of sane order recently. > dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk; > - else if (IS_GEN5(dev_priv)) > - dev_priv->display.get_cdclk = fixed_450mhz_get_cdclk; > - else if (IS_GM45(dev_priv)) > - dev_priv->display.get_cdclk = gm45_get_cdclk; > - else if (IS_G45(dev_priv)) > + break; > + case INTEL_I945GM: > + dev_priv->display.get_cdclk = i945gm_get_cdclk; > + break; > + case INTEL_G33: > + case INTEL_G45: More disorder. > dev_priv->display.get_cdclk = g33_get_cdclk; > - else if (IS_I965GM(dev_priv)) > - dev_priv->display.get_cdclk = i965gm_get_cdclk; > - else if (IS_I965G(dev_priv)) > - dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk; > - else if (IS_PINEVIEW(dev_priv)) > + break; > + case INTEL_PINEVIEW: > dev_priv->display.get_cdclk = pnv_get_cdclk; > - else if (IS_G33(dev_priv)) > - dev_priv->display.get_cdclk = g33_get_cdclk; > - else if (IS_I945GM(dev_priv)) > - dev_priv->display.get_cdclk = i945gm_get_cdclk; > - else if (IS_I945G(dev_priv)) > - dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk; > - else if (IS_I915GM(dev_priv)) > - dev_priv->display.get_cdclk = i915gm_get_cdclk; > - else if (IS_I915G(dev_priv)) > - dev_priv->display.get_cdclk = fixed_333mhz_get_cdclk; > - else if (IS_I865G(dev_priv)) > - dev_priv->display.get_cdclk = fixed_266mhz_get_cdclk; > - else if (IS_I85X(dev_priv)) > - dev_priv->display.get_cdclk = i85x_get_cdclk; > - else if (IS_I845G(dev_priv)) > - dev_priv->display.get_cdclk = fixed_200mhz_get_cdclk; > - else { /* 830 */ > - WARN(!IS_I830(dev_priv), > - "Unknown platform. Assuming 133 MHz CDCLK\n"); > - dev_priv->display.get_cdclk = fixed_133mhz_get_cdclk; > + break; > + case INTEL_I965GM: > + dev_priv->display.get_cdclk = i965gm_get_cdclk; > + break; > + case INTEL_GM45: > + dev_priv->display.get_cdclk = gm45_get_cdclk; > + break; > + case INTEL_IRONLAKE: > + dev_priv->display.get_cdclk = fixed_450mhz_get_cdclk; > + break; > + case INTEL_VALLEYVIEW: > + case INTEL_CHERRYVIEW: > + dev_priv->display.get_cdclk = vlv_get_cdclk; > + break; > + case INTEL_HASWELL: > + dev_priv->display.get_cdclk = hsw_get_cdclk; > + break; > + case INTEL_BROADWELL: > + dev_priv->display.get_cdclk = bdw_get_cdclk; > + break; > + case INTEL_SKYLAKE: > + case INTEL_KABYLAKE: > + dev_priv->display.get_cdclk = skl_get_cdclk; > + break; > + case INTEL_BROXTON: > + case INTEL_GEMINILAKE: > + dev_priv->display.get_cdclk = bxt_get_cdclk; > + break; > } > } > -- > 2.7.4 > > _______________________________________________ > Intel-gfx mailing list > [email protected] > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Ville Syrjälä Intel OTC _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
