Re: [PATCH v3 05/14] drm: bridge/analogix_dp: fix link_rate & lane_count bug

From: Jingoo Han <jingoohan1@gmail.com>
To: Yakir Yang <ykk@rock-chips.com>
Cc: Heiko Stuebner <heiko@sntech.de>,
	Thierry Reding <treding@nvidia.com>,
	Fabio Estevam <fabio.estevam@freescale.com>,
	Inki Dae <inki.dae@samsung.com>,
	"joe@perches.com" <joe@perches.com>,
	Russell King <rmk+kernel@arm.linux.org.uk>,
	"djkurtz@google.com" <djkurtz@google.com>,
	"dianders@google.com" <dianders@google.com>,
	"seanpaul@google.com" <seanpaul@google.com>,
	Takashi Iwai <tiwai@suse.de>,
	"ajaynumb@gmail.com" <ajaynumb@gmail.com>,
	Andrzej Hajda <a.hajda@samsung.com>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	David Airlie <airlied@linux.ie>,
	Gustavo Padovan <gustavo.padovan@collabora.co.uk>,
	Vincent Palatin <vpalatin@chromium.org>,
	Mark Yao <mark.yao@rock-chips.com>,
	Andy Yan <andy.yan@rock-chips.com>,
	Kumar Gala <galak@codeaurora.org>,
	Ian Campbell <ijc+devicetree@hellion.org.uk>,
	Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
	Kishon Vijay Abraham I <kishon@ti.com>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
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	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-samsung-soc@vger.kernel.org" 
	<linux-samsung-soc@vger.kernel.org>,
	"linux-rockchip@lists.infradead.org" 
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	"jingoohan1@gmail.com" <jingoohan1@gmail.com>
Subject: Re: [PATCH v3 05/14] drm: bridge/analogix_dp: fix link_rate & lane_count bug
Date: Thu, 20 Aug 2015 16:22:43 +0900	[thread overview]
Message-ID: <6480369A-D108-4FBD-9041-ED925D8FD922@gmail.com> (raw)
In-Reply-To: <1439995824-18312-1-git-send-email-ykk@rock-chips.com>

On 2015. 8. 19., at PM 11:50, Yakir Yang <ykk@rock-chips.com> wrote:
> 
> link_rate and lane_count already configed in analogix_dp_set_link_train(),

s/configed/configured

Also, the commit name such as "fix ... bug" is not good.
How about following?

drm: bridge/analogix_dp: remove duplicate configuration of link rate and link count

Best regards,
Jingoo Han

> so we don't need to config those repeatly after training finished, just
> remove them out.
> 
> Beside Display Port 1.2 already support 5.4Gbps link rate, the maximum sets
> would change from {1.62Gbps, 2.7Gbps} to {1.62Gbps, 2.7Gbps, 5.4Gbps}.
> 
> Signed-off-by: Yakir Yang <ykk@rock-chips.com>
> ---
> Changes in v3:
> - Take Thierry Reding suggest, link_rate and lane_count shouldn't config to
>  the DT property value directly, but we can take those as hardware limite.
>  For example, RK3288 only support 4 physical lanes of 2.7/1.62 Gbps/lane,
>  so DT property would like "link-rate = 0x0a" "lane-count = 4".
> 
> Changes in v2: None
> 
> drivers/gpu/drm/bridge/analogix_dp_core.c | 16 ++++++++--------
> drivers/gpu/drm/bridge/analogix_dp_core.h |  9 +++++----
> 2 files changed, 13 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix_dp_core.c
> index 480cc13..1778e0a 100644
> --- a/drivers/gpu/drm/bridge/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix_dp_core.c
> @@ -635,6 +635,8 @@ static void analogix_dp_get_max_rx_bandwidth(struct analogix_dp_device *dp,
>    /*
>     * For DP rev.1.1, Maximum link rate of Main Link lanes
>     * 0x06 = 1.62 Gbps, 0x0a = 2.7 Gbps
> +     * For DP rev.1.2, Maximum link rate of Main Link lanes
> +     * 0x06 = 1.62 Gbps, 0x0a = 2.7 Gbps, 0x14 = 5.4Gbps
>     */
>    analogix_dp_read_byte_from_dpcd(dp, DP_MAX_LINK_RATE, &data);
>    *bandwidth = data;
> @@ -668,7 +670,8 @@ static void analogix_dp_init_training(struct analogix_dp_device *dp,
>    analogix_dp_get_max_rx_lane_count(dp, &dp->link_train.lane_count);
> 
>    if ((dp->link_train.link_rate != LINK_RATE_1_62GBPS) &&
> -        (dp->link_train.link_rate != LINK_RATE_2_70GBPS)) {
> +        (dp->link_train.link_rate != LINK_RATE_2_70GBPS) &&
> +        (dp->link_train.link_rate != LINK_RATE_5_40GBPS)) {
>        dev_err(dp->dev, "Rx Max Link Rate is abnormal :%x !\n",
>            dp->link_train.link_rate);
>        dp->link_train.link_rate = LINK_RATE_1_62GBPS;
> @@ -901,8 +904,8 @@ static void analogix_dp_commit(struct analogix_dp_device *dp)
>        return;
>    }
> 
> -    ret = analogix_dp_set_link_train(dp, dp->video_info->lane_count,
> -                     dp->video_info->link_rate);
> +    ret = analogix_dp_set_link_train(dp, dp->video_info->max_lane_count,
> +                     dp->video_info->max_link_rate);
>    if (ret) {
>        dev_err(dp->dev, "unable to do link train\n");
>        return;
> @@ -912,9 +915,6 @@ static void analogix_dp_commit(struct analogix_dp_device *dp)
>    analogix_dp_enable_rx_to_enhanced_mode(dp, 1);
>    analogix_dp_enable_enhanced_mode(dp, 1);
> 
> -    analogix_dp_set_lane_count(dp, dp->video_info->lane_count);
> -    analogix_dp_set_link_bandwidth(dp, dp->video_info->link_rate);
> -
>    analogix_dp_init_video(dp);
>    ret = analogix_dp_config_video(dp);
>    if (ret)
> @@ -1198,13 +1198,13 @@ static struct video_info *analogix_dp_dt_parse_pdata(struct device *dev)
>    }
> 
>    if (of_property_read_u32(dp_node, "analogix,link-rate",
> -                 &dp_video_config->link_rate)) {
> +                 &dp_video_config->max_link_rate)) {
>        dev_err(dev, "failed to get link-rate\n");
>        return ERR_PTR(-EINVAL);
>    }
> 
>    if (of_property_read_u32(dp_node, "analogix,lane-count",
> -                 &dp_video_config->lane_count)) {
> +                 &dp_video_config->max_lane_count)) {
>        dev_err(dev, "failed to get lane-count\n");
>        return ERR_PTR(-EINVAL);
>    }
> diff --git a/drivers/gpu/drm/bridge/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix_dp_core.h
> index 2cefde9..941b34f 100644
> --- a/drivers/gpu/drm/bridge/analogix_dp_core.h
> +++ b/drivers/gpu/drm/bridge/analogix_dp_core.h
> @@ -21,8 +21,9 @@
> #define MAX_EQ_LOOP 5
> 
> enum link_rate_type {
> -    LINK_RATE_1_62GBPS = 0x06,
> -    LINK_RATE_2_70GBPS = 0x0a
> +    LINK_RATE_1_62GBPS = DP_LINK_BW_1_62,
> +    LINK_RATE_2_70GBPS = DP_LINK_BW_2_7,
> +    LINK_RATE_5_40GBPS = DP_LINK_BW_5_4,
> };
> 
> enum link_lane_count_type {
> @@ -128,8 +129,8 @@ struct video_info {
>    enum color_coefficient ycbcr_coeff;
>    enum color_depth color_depth;
> 
> -    enum link_rate_type link_rate;
> -    enum link_lane_count_type lane_count;
> +    enum link_rate_type       max_link_rate;
> +    enum link_lane_count_type max_lane_count;
> };
> 
> struct link_train {
> -- 
> 1.9.1
> 
> 