From: Sam Ravnborg <sam@ravnborg.org>
To: Jonathan Liu <net147@gmail.com>,
Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Fabio Estevam <fabio.estevam@freescale.com>,
Jernej Skrabec <jernej.skrabec@siol.net>,
Jonas Karlman <jonas@kwiboo.se>, David Airlie <airlied@linux.ie>,
Neil Armstrong <narmstrong@baylibre.com>,
linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
Andrzej Hajda <a.hajda@samsung.com>,
linux-rockchip@lists.infradead.org,
Boris Brezillon <boris.brezillon@collabora.com>,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
Russell King <rmk+kernel@arm.linux.org.uk>,
Liu Ying <victor.liu@nxp.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] drm: bridge: dw-hdmi: Avoid resetting force in the detect function
Date: Sun, 8 Nov 2020 10:53:22 +0100 [thread overview]
Message-ID: <20201108095322.GA1129714@ravnborg.org> (raw)
In-Reply-To: <20201031081747.372599-1-net147@gmail.com>
Russell,
On Sat, Oct 31, 2020 at 07:17:47PM +1100, Jonathan Liu wrote:
> It has been observed that resetting force in the detect function can
> result in the PHY being powered down in response to hot-plug detect
> being asserted, even when the HDMI connector is forced on.
>
> Enabling debug messages and adding a call to dump_stack() in
> dw_hdmi_phy_power_off() shows the following in dmesg:
> [ 160.637413] dwhdmi-rockchip ff940000.hdmi: EVENT=plugin
> [ 160.637433] dwhdmi-rockchip ff940000.hdmi: PHY powered down in 0 iterations
>
> Call trace:
> dw_hdmi_phy_power_off
> dw_hdmi_phy_disable
> dw_hdmi_update_power
> dw_hdmi_detect
> dw_hdmi_connector_detect
> drm_helper_probe_detect_ctx
> drm_helper_hpd_irq_event
> dw_hdmi_irq
> irq_thread_fn
> irq_thread
> kthread
> ret_from_fork
>
> Fixes: 381f05a7a842 ("drm: bridge/dw_hdmi: add connector mode forcing")
> Signed-off-by: Jonathan Liu <net147@gmail.com>
you are the original author of this code - any comments on this patch?
Sam
> ---
> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 6 ------
> 1 file changed, 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index 748df1cacd2b..0c79a9ba48bb 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -2327,12 +2327,6 @@ static enum drm_connector_status dw_hdmi_detect(struct dw_hdmi *hdmi)
> {
> enum drm_connector_status result;
>
> - mutex_lock(&hdmi->mutex);
> - hdmi->force = DRM_FORCE_UNSPECIFIED;
> - dw_hdmi_update_power(hdmi);
> - dw_hdmi_update_phy_mask(hdmi);
> - mutex_unlock(&hdmi->mutex);
> -
> result = hdmi->phy.ops->read_hpd(hdmi, hdmi->phy.data);
>
> mutex_lock(&hdmi->mutex);
> --
> 2.29.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
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next prev parent reply other threads:[~2020-11-08 9:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-31 8:17 [PATCH] drm: bridge: dw-hdmi: Avoid resetting force in the detect function Jonathan Liu
2020-11-08 9:53 ` Sam Ravnborg [this message]
2020-11-08 9:57 ` Russell King - ARM Linux admin
2020-11-08 10:47 ` Sam Ravnborg
2020-11-11 7:59 ` Jonathan Liu
2020-11-12 21:22 ` Sam Ravnborg
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