Hi, Bo-Chen: On Fri, 2022-07-01 at 14:28 +0800, Bo-Chen Chen wrote: > From: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx> > > This patch adds a embedded displayport driver for the MediaTek mt8195 > SoC. > > It supports the MT8195, the embedded DisplayPort units. It offers > 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 > Jitao shi <jitao.shi@xxxxxxxxxxxx> > > Signed-off-by: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx> > Signed-off-by: Guillaume Ranquet <granquet@xxxxxxxxxxxx> > Signed-off-by: Bo-Chen Chen <rex-bc.chen@xxxxxxxxxxxx> > --- [snip] > + > +static irqreturn_t mtk_dp_hpd_event_thread(int hpd, void *dev) > +{ > + struct mtk_dp *mtk_dp = dev; > + u8 buf[DP_RECEIVER_CAP_SIZE] = {}; > + > + if (mtk_dp->train_info.cable_state_change) { > + mtk_dp->train_info.cable_state_change = false; > + > + mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE, > + DP_PWR_STATE_BANDGAP_TPLL_LANE, > + DP_PWR_STATE_MASK); > + drm_dp_read_dpcd_caps(&mtk_dp->aux, buf); Why do you read dpcd caps into 'buf'. 'buf' is not used elsewhere. Regards, CK > + } > + > + if (mtk_dp->train_info.irq_sta.hpd_inerrupt) { > + dev_dbg(mtk_dp->dev, "MTK_DP_HPD_INTERRUPT\n"); > + mtk_dp->train_info.irq_sta.hpd_inerrupt = false; > + mtk_dp_hpd_sink_event(mtk_dp); > + } > + > + return IRQ_HANDLED; > +} > +