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Message-ID: <CAOw6vbKVkbqo9ZeCOgpBw9aGceF_vu93hMVThj2nwVM0x+rv-Q@mail.gmail.com>
Date: Tue, 6 Sep 2016 15:51:34 -0400
From: Sean Paul <seanpaul@...omium.org>
To: Yakir Yang <ykk@...k-chips.com>
Cc: Daniel Vetter <daniel.vetter@...ll.ch>,
Inki Dae <inki.dae@...sung.com>,
Stéphane Marchesin <marcheu@...omium.org>,
Tomasz Figa <tfiga@...omium.org>,
Douglas Anderson <dianders@...omium.org>,
Thierry Reding <treding@...dia.com>,
Krzysztof Kozlowski <k.kozlowski@...sung.com>,
Heiko Stuebner <heiko@...ech.de>,
Jingoo Han <jingoohan1@...il.com>,
David Airlie <airlied@...ux.ie>,
Javier Martinez Canillas <javier@....samsung.com>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
dri-devel <dri-devel@...ts.freedesktop.org>,
linux-samsung-soc <linux-samsung-soc@...r.kernel.org>,
linux-rockchip@...ts.infradead.org
Subject: Re: [PATCH] drm/bridge: analogix_dp: detect Sink PSR state after
configuring the PSR
On Fri, Aug 26, 2016 at 6:19 AM, Yakir Yang <ykk@...k-chips.com> wrote:
> Make sure the request PSR state could effect in analogix_dp_send_psr_spd()
> function, or printing the error Sink PSR state if we failed to effect
> the request PSR setting.
>
> Signed-off-by: Yakir Yang <ykk@...k-chips.com>
> ---
> drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 6 ++---
> drivers/gpu/drm/bridge/analogix/analogix_dp_core.h | 4 ++--
> drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c | 26 ++++++++++++++++++++--
> 3 files changed, 28 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> index efac8ab..5a37de8 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -115,8 +115,7 @@ int analogix_dp_enable_psr(struct device *dev)
> psr_vsc.DB0 = 0;
> psr_vsc.DB1 = EDP_VSC_PSR_STATE_ACTIVE | EDP_VSC_PSR_CRC_VALUES_VALID;
>
> - analogix_dp_send_psr_spd(dp, &psr_vsc);
> - return 0;
> + return analogix_dp_send_psr_spd(dp, &psr_vsc);
> }
> EXPORT_SYMBOL_GPL(analogix_dp_enable_psr);
>
> @@ -138,8 +137,7 @@ int analogix_dp_disable_psr(struct device *dev)
> psr_vsc.DB0 = 0;
> psr_vsc.DB1 = 0;
>
> - analogix_dp_send_psr_spd(dp, &psr_vsc);
> - return 0;
> + return analogix_dp_send_psr_spd(dp, &psr_vsc);
> }
> EXPORT_SYMBOL_GPL(analogix_dp_disable_psr);
>
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
> index 473b980..f617a9d 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
> @@ -283,7 +283,7 @@ void analogix_dp_config_video_slave_mode(struct analogix_dp_device *dp);
> void analogix_dp_enable_scrambling(struct analogix_dp_device *dp);
> void analogix_dp_disable_scrambling(struct analogix_dp_device *dp);
> void analogix_dp_enable_psr_crc(struct analogix_dp_device *dp);
> -void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
> - struct edp_vsc_psr *vsc);
> +int analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
> + struct edp_vsc_psr *vsc);
>
> #endif /* _ANALOGIX_DP_CORE_H */
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> index 52c1b6b..505e9d8 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> @@ -1328,9 +1328,11 @@ void analogix_dp_enable_psr_crc(struct analogix_dp_device *dp)
> writel(PSR_VID_CRC_ENABLE, dp->reg_base + ANALOGIX_DP_CRC_CON);
> }
>
> -void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
> - struct edp_vsc_psr *vsc)
> +int analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
> + struct edp_vsc_psr *vsc)
> {
> + unsigned long timeout;
> + unsigned char sink;
u8
> unsigned int val;
>
> /* don't send info frame */
> @@ -1372,4 +1374,24 @@ void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
> val = readl(dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
> val |= IF_EN;
> writel(val, dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
> +
> + timeout = jiffies + msecs_to_jiffies(100);
Pull 100 out into a #define
> + while (1) {
> + analogix_dp_read_byte_from_dpcd(dp, DP_PSR_STATUS, &sink);
You should be checking return value here.
> +
> + if (vsc->DB1 && sink == DP_PSR_SINK_ACTIVE_RFB)
> + break;
> +
> + if (!vsc->DB1 && sink == DP_PSR_SINK_INACTIVE)
> + break;
> +
> + if (time_after(jiffies, timeout)) {
> + dev_warn(dp->dev, "Failed to effect PSR: %x", sink);
> + return -EBUSY;
-ETIMEDOUT is more appropriate
> + }
> +
> + usleep_range(1000, 1500);
> + }
The while(1) loop is a little scary. I'd rather do:
while (time_before(jiffies, timeout)) {
ret = analogix_dp_read_byte_from_dpcd(dp, DP_PSR_STATUS, &sink);
if (ret != 1) {
DRM_DEV_ERROR(dp->dev, "PSR_STATUS read failed
ret=%d", ret);
return ret;
}
if (vsc->DB1 && sink == DP_PSR_SINK_ACTIVE_RFB ||
!vsc->DB1 && sink == DP_PSR_SINK_INACTIVE)
return 0;
usleep_range(1000, 1500);
}
dev_warn(dp->dev, "Failed to effect PSR: %x", sink);
return -ETIMEDOUT;
> +
> + return 0;
> }
> --
> 1.9.1
>
>
> --
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