Hi, Louis: Louis-Alexis Eyraud <[email protected]> 於 2025年12月5日週五 下午2:22寫道： > > During a read or write transfer, the mtk_hdmi_ddc_v2 driver polls the > DDC_I2C_IN_PROG bit of HPD_DDC_STATUS register to check if the transfer > completes but do no particular action if a timeout is reached. It could > lead the next transfer attempts to fail because the faulty transfer was > not aborted. So, add in both low level read and write functions a abort > action by writing the DDC_CTRL register with the ABORT_XFER command > value.
Applied to mediatek-drm-fixes [1], thanks. [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-fixes Regards, Chun-Kuang. > > Fixes: 8d0f79886273 ("drm/mediatek: Introduce HDMI/DDC v2 for MT8195/MT8188") > Signed-off-by: Louis-Alexis Eyraud <[email protected]> > --- > drivers/gpu/drm/mediatek/mtk_hdmi_ddc_v2.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi_ddc_v2.c > b/drivers/gpu/drm/mediatek/mtk_hdmi_ddc_v2.c > index > b844e2c10f28060baef64bd36c5464758b08e162..6ae7cbba8cb6dacf46c2f7ab74a2d7446d698b69 > 100644 > --- a/drivers/gpu/drm/mediatek/mtk_hdmi_ddc_v2.c > +++ b/drivers/gpu/drm/mediatek/mtk_hdmi_ddc_v2.c > @@ -96,6 +96,11 @@ static int mtk_ddc_wr_one(struct mtk_hdmi_ddc *ddc, u16 > addr_id, > !(val & DDC_I2C_IN_PROG), 500, 1000); > if (ret) { > dev_err(ddc->dev, "DDC I2C write timeout\n"); > + > + /* Abort transfer if it is still in progress */ > + regmap_update_bits(ddc->regs, DDC_CTRL, DDC_CTRL_CMD, > + FIELD_PREP(DDC_CTRL_CMD, > DDC_CMD_ABORT_XFER)); > + > return ret; > } > > @@ -179,6 +184,11 @@ static int mtk_ddcm_read_hdmi(struct mtk_hdmi_ddc *ddc, > u16 uc_dev, > 500 * (temp_length + 5)); > if (ret) { > dev_err(ddc->dev, "Timeout waiting for DDC I2C\n"); > + > + /* Abort transfer if it is still in progress */ > + regmap_update_bits(ddc->regs, DDC_CTRL, DDC_CTRL_CMD, > + FIELD_PREP(DDC_CTRL_CMD, > DDC_CMD_ABORT_XFER)); > + > return ret; > } > > > -- > 2.52.0 >
