lkml.org 
[lkml]   [2022]   [Aug]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v15 05/11] drm/mediatek: Add MT8195 Embedded DisplayPort driver
From
Date
Hi, Bo-Chen:

On Wed, 2022-07-27 at 12:50 +0800, Bo-Chen Chen wrote:
> From: Markus Schneider-Pargmann <msp@baylibre.com>
>
> 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@mediatek.com>
>
> Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
> Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
> Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
> ---

[snip]

> +
> +static irqreturn_t mtk_dp_hpd_event_thread(int hpd, void *dev)
> +{
> + struct mtk_dp *mtk_dp = dev;
> +
> + if (mtk_dp->train_info.hpd_inerrupt) {

When the thread is running, mtk_dp->train_info.hpd_inerrupt would be
true. So this checking is redundant.

> + dev_dbg(mtk_dp->dev, "MTK_DP_HPD_INTERRUPT\n");
> + mtk_dp->train_info.hpd_inerrupt = false;
> + mtk_dp_hpd_sink_event(mtk_dp);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t mtk_dp_hpd_event(int hpd, void *dev)
> +{
> + struct mtk_dp *mtk_dp = dev;
> + struct mtk_dp_train_info *train_info = &mtk_dp->train_info;
> + u32 irq_status;
> +
> + irq_status = mtk_dp_read(mtk_dp, MTK_DP_TOP_IRQ_STATUS);
> +
> + if (!irq_status)
> + return IRQ_HANDLED;
> +
> + if (irq_status & RGS_IRQ_STATUS_TRANSMITTER) {

Combine this if-checking with previous if-checking, it would be:

if (!(irq_status & RGS_IRQ_STATUS_TRANSMITTER))
return IRQ_HANDLED;

> + irq_status = mtk_dp_swirq_get_clear(mtk_dp) |
> + mtk_dp_hwirq_get_clear(mtk_dp);
> +
> + if (!irq_status)
> + return IRQ_HANDLED;
> +
> + if (irq_status & MTK_DP_HPD_INTERRUPT)

Does this interrupt MTK_DP_HPD_INTERRUPT have any relation with
MTK_DP_HPD_CONNECT and MTK_DP_HPD_CONNECT? From the naming, I guess
that when MTK_DP_HPD_CONNECT happen, MTK_DP_HPD_INTERRUPT would also
happen. Either for MTK_DP_HPD_DISCONNECT. When would
MTK_DP_HPD_INTERRUPT happen but MTK_DP_HPD_CONNECT or
MTK_DP_HPD_DISCONNECT does not happen.

Regards,
CK

> + train_info->hpd_inerrupt = true;
> +
> + if (!(irq_status & MTK_DP_HPD_CONNECT ||
> + irq_status & MTK_DP_HPD_DISCONNECT))
> + return IRQ_WAKE_THREAD;
> +
> + if (!!(mtk_dp_read(mtk_dp, MTK_DP_TRANS_P0_3414) &
> + HPD_DB_DP_TRANS_P0_MASK))
> + train_info->cable_plugged_in = true;
> + else
> + train_info->cable_plugged_in = false;
> +
> + mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
> + DP_PWR_STATE_BANDGAP_TPLL_LANE,
> + DP_PWR_STATE_MASK);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +

\
 
 \ /
  Last update: 2022-08-02 07:09    [W:0.141 / U:1.164 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site