Quoting Marijn Suijten (2021-08-30 15:45:42) > Hi Stephen, > > On 2021-08-30 15:16:13, Stephen Boyd wrote: > > Quoting Marijn Suijten (2021-08-30 11:24:44) > > > All DSI PHY/PLL drivers were referencing their VCO parent clock by a > > > global name, most of which don't exist or have been renamed. These > > > clock drivers seem to function fine without that except the 14nm driver > > > for the sdm6xx [1]. > > > > > > At the same time all DTs provide a "ref" clock as per the requirements > > > of dsi-phy-common.yaml, but the clock is never used. This patchset puts > > > that clock to use without relying on a global clock name, so that all > > > dependencies are explicitly defined in DT (the firmware) in the end. > > > > > > Note that msm8974 is the only board not providing this clock, and > > > apq8064 was providing the wrong clock (19.2MHz cxo instead of 27MHz > > > pxo). Both have been been addressed in separate patches that are > > > supposed to land well in advance of this patchset. > > > > > > Furthermore not all board-DTs provided this clock initially but that > > > deficiency has been addressed in followup patches (see the Fixes: > > > below). Those commits seem to assume that the clock was used, while > > > nothing in history indicates that this "ref" clock was ever retrieved. > > > > > > [1]: https://lore.kernel.org/linux-arm-msm/386db1a6-a1cd-3c7d-a88e-dc83f8a1be96@xxxxxxxxxxxxxx/ > > > > > > Fixes: 79e51645a1dd ("arm64: dts: qcom: msm8916: Set 'xo_board' as ref clock of the DSI PHY") > > > Fixes: 6969d1d9c615 ("ARM: dts: qcom-apq8064: Set 'cxo_board' as ref clock of the DSI PHY") > > > Fixes: 0c0e72705a33 ("arm64: dts: sdm845: Set 'bi_tcxo' as ref clock of the DSI PHYs") > > > Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx> > > > --- > > > drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c | 4 +++- > > > drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c | 4 +++- > > > drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c | 4 +++- > > > drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm_8960.c | 4 +++- > > > drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c | 4 +++- > > > 5 files changed, 15 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c > > > index e46b10fc793a..3cbb1f1475e8 100644 > > > --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c > > > +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c > > > @@ -562,7 +562,9 @@ static int pll_10nm_register(struct dsi_pll_10nm *pll_10nm, struct clk_hw **prov > > > char clk_name[32], parent[32], vco_name[32]; > > > char parent2[32], parent3[32], parent4[32]; > > > struct clk_init_data vco_init = { > > > - .parent_names = (const char *[]){ "xo" }, > > > + .parent_data = &(const struct clk_parent_data) { > > > + .fw_name = "ref", > > > > Please also add .name as the old parent_names value so that newer > > kernels can be used without having to use new DT. > > We discussed that only msm8974 misses this "ref" clock at the time of > writing. Aforementioned Fixes: patches have all been merged about 3 > years ago, are those DTs still in use with a newer kernel? I suppose > this patch is only backported to kernels including those DT patches, is > it reasonable to assume that at least that DT is in use there? I have no idea. > > Besides, not all clock trees provide this global "xo" or "bi_tcxo" clock > in the first place. > It doesn't hurt to also specify a .name to help migrate anything else over. Unless you're confident it won't cause problems to rely on proper DT being used?
