Hi Angelo, Quoting AngeloGioacchino Del Regno (2021-12-10 11:17:44) > Il 10/11/21 14:06, Guillaume Ranquet ha scritto: > > From: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx> > > > > This patch adds a DisplayPort driver for the Mediatek mt8195 SoC and a > > according phy driver mediatek-dp-phy. > > > > It supports both functional units on the mt8195, the embedded > > DisplayPort as well as the external DisplayPort units. It offers > > hot-plug-detection, audio up to 8 channels, and DisplayPort 1.4 with up > > to 4 lanes. > > > > The driver creates a child device for the phy. The child device will > > never exist without the parent being active. As they are sharing a > > register range, the parent passes a regmap pointer to the child so that > > both can work with the same register range. The phy driver sets device > > data that is read by the parent to get the phy device that can be used > > to control the phy properties. > > > > This driver is based on an initial version by > > Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>. > > > > Signed-off-by: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx> > > Signed-off-by: Guillaume Ranquet <granquet@xxxxxxxxxxxx> > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > > Hello Markus, Guillaume, > > there is a critical issue with this patch. Please check below. > > > --- > > drivers/gpu/drm/drm_edid.c | 2 +- > > drivers/gpu/drm/mediatek/Kconfig | 7 + > > drivers/gpu/drm/mediatek/Makefile | 2 + > > drivers/gpu/drm/mediatek/mtk_dp.c | 3094 +++++++++++++++++++++++ > > drivers/gpu/drm/mediatek/mtk_dp_reg.h | 568 +++++ > > drivers/gpu/drm/mediatek/mtk_dpi.c | 111 +- > > drivers/gpu/drm/mediatek/mtk_dpi_regs.h | 26 + > > drivers/gpu/drm/mediatek/mtk_drm_drv.c | 1 + > > drivers/gpu/drm/mediatek/mtk_drm_drv.h | 1 + > > 9 files changed, 3799 insertions(+), 13 deletions(-) > > create mode 100644 drivers/gpu/drm/mediatek/mtk_dp.c > > create mode 100644 drivers/gpu/drm/mediatek/mtk_dp_reg.h > > > > <snip> > > > diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c > > index 384074f69111b..e6e88e3cd811d 100644 > > --- a/drivers/gpu/drm/mediatek/mtk_dpi.c > > +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c > > <snip> > > > @@ -979,6 +1051,16 @@ static int mtk_dpi_probe(struct platform_device *pdev) > > return ret; > > } > > > > + dpi->dpi_ck_cg = devm_clk_get(dev, "ck_cg"); > > mtk_dpi is used on MT2701, MT7183, MT8183, MT8192, but these platforms haven't > got any "ck_cg" clock defined in their device-trees (regardless of whether these > can support adding this clock or not, any code change shall be retro-compatible > hence not breaking compatibility/functionality with older device-trees). > > Reminding that: > - mediatek-drm uses the component framework > - mtk_drm_drv is the component master > - mtk_drm_drv bind() won't be called unless all of the components added with > match aren't calling component_add() > > ... this change not only breaks DisplayPort support for *all* of the > aforementioned SoCs, but also makes the entire mediatek-drm to not finish > probing, producing a global breakage that also includes DSI and the entire > stack of components of that master (so, no display on all of them). > > To avoid breaking any SoC that's not MT8195, please use devm_clk_get_optional() > here in the next version. > > Thanks, > - Angelo > This is a good catch, I will update for v7. Thank you very much for your review. Thx, Guillaume.
