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Subject: Re: [PATCH] drm/bridge/synopsys: dw-hdmi: fix dw_hdmi_setup_rx_sense
To:     Neil Armstrong <narmstrong@baylibre.com>, a.hajda@samsung.com,
        jernej.skrabec@siol.net
Cc:     dri-devel@lists.freedesktop.org, linux-amlogic@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
References: <1527673438-20643-1-git-send-email-narmstrong@baylibre.com>
From:   Archit Taneja <architt@codeaurora.org>
Message-ID: <db0013e7-dbde-13ca-b9af-178f4b3cfff6@codeaurora.org>
Date:   Thu, 31 May 2018 11:30:41 +0530
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On Wednesday 30 May 2018 03:13 PM, Neil Armstrong wrote:
> The dw_hdmi_setup_rx_sense exported function should not use struct device
> to recover the dw-hdmi context using drvdata, but take struct dw_hdmi
> directly like other exported functions.
> 
> This caused a regression using Meson DRM on S905X since v4.17-rc1 :

Reviewed-by: Archit Taneja <architt@codeaurora.org>

> 
> Internal error: Oops: 96000007 [#1] PREEMPT SMP
> [...]
> CPU: 0 PID: 124 Comm: irq/32-dw_hdmi_ Not tainted 4.17.0-rc7 #2
> Hardware name: Libre Technology CC (DT)
> [...]
> pc : osq_lock+0x54/0x188
> lr : __mutex_lock.isra.0+0x74/0x530
> [...]
> Process irq/32-dw_hdmi_ (pid: 124, stack limit = 0x00000000adf418cb)
> Call trace:
>    osq_lock+0x54/0x188
>    __mutex_lock_slowpath+0x10/0x18
>    mutex_lock+0x30/0x38
>    __dw_hdmi_setup_rx_sense+0x28/0x98
>    dw_hdmi_setup_rx_sense+0x10/0x18
>    dw_hdmi_top_thread_irq+0x2c/0x50
>    irq_thread_fn+0x28/0x68
>    irq_thread+0x10c/0x1a0
>    kthread+0x128/0x130
>    ret_from_fork+0x10/0x18
>   Code: 34000964 d00050a2 51000484 9135c042 (f864d844)
>   ---[ end trace 945641e1fbbc07da ]---
>   note: irq/32-dw_hdmi_[124] exited with preempt_count 1
>   genirq: exiting task "irq/32-dw_hdmi_" (124) is an active IRQ thread (irq 32)
> 
> Fixes: eea034af90c6 ("drm/bridge/synopsys: dw-hdmi: don't clobber drvdata")
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> Tested-by: Koen Kooi <koen@dominion.thruhere.net>
> ---
>   drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 15 ++++-----------
>   drivers/gpu/drm/meson/meson_dw_hdmi.c     |  2 +-
>   include/drm/bridge/dw_hdmi.h              |  2 +-
>   3 files changed, 6 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index ec8d000..3c136f2b 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -2077,7 +2077,7 @@ static irqreturn_t dw_hdmi_hardirq(int irq, void *dev_id)
>   	return ret;
>   }
>   
> -void __dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense)
> +void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense)
>   {
>   	mutex_lock(&hdmi->mutex);
>   
> @@ -2103,13 +2103,6 @@ void __dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense)
>   	}
>   	mutex_unlock(&hdmi->mutex);
>   }
> -
> -void dw_hdmi_setup_rx_sense(struct device *dev, bool hpd, bool rx_sense)
> -{
> -	struct dw_hdmi *hdmi = dev_get_drvdata(dev);
> -
> -	__dw_hdmi_setup_rx_sense(hdmi, hpd, rx_sense);
> -}
>   EXPORT_SYMBOL_GPL(dw_hdmi_setup_rx_sense);
>   
>   static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
> @@ -2145,9 +2138,9 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
>   	 */
>   	if (intr_stat &
>   	    (HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD)) {
> -		__dw_hdmi_setup_rx_sense(hdmi,
> -					 phy_stat & HDMI_PHY_HPD,
> -					 phy_stat & HDMI_PHY_RX_SENSE);
> +		dw_hdmi_setup_rx_sense(hdmi,
> +				       phy_stat & HDMI_PHY_HPD,
> +				       phy_stat & HDMI_PHY_RX_SENSE);
>   
>   		if ((phy_stat & (HDMI_PHY_RX_SENSE | HDMI_PHY_HPD)) == 0)
>   			cec_notifier_set_phys_addr(hdmi->cec_notifier,
> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> index a393095..c9ad456 100644
> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> @@ -529,7 +529,7 @@ static irqreturn_t dw_hdmi_top_thread_irq(int irq, void *dev_id)
>   		if (stat & HDMITX_TOP_INTR_HPD_RISE)
>   			hpd_connected = true;
>   
> -		dw_hdmi_setup_rx_sense(dw_hdmi->dev, hpd_connected,
> +		dw_hdmi_setup_rx_sense(dw_hdmi->hdmi, hpd_connected,
>   				       hpd_connected);
>   
>   		drm_helper_hpd_irq_event(dw_hdmi->encoder.dev);
> diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
> index dd2a8cf..ccb5aa8 100644
> --- a/include/drm/bridge/dw_hdmi.h
> +++ b/include/drm/bridge/dw_hdmi.h
> @@ -151,7 +151,7 @@ struct dw_hdmi *dw_hdmi_bind(struct platform_device *pdev,
>   			     struct drm_encoder *encoder,
>   			     const struct dw_hdmi_plat_data *plat_data);
>   
> -void dw_hdmi_setup_rx_sense(struct device *dev, bool hpd, bool rx_sense);
> +void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense);
>   
>   void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate);
>   void dw_hdmi_audio_enable(struct dw_hdmi *hdmi);
>