[PATCH RESEND v2 2/2] drm/bridge: dw-hdmi: Always add the bridge in the global bridge list

Liu Ying victor.liu at nxp.com
Sat Jul 11 00:59:53 UTC 2020


On Fri, 2020-07-10 at 19:32 +0200, Sam Ravnborg wrote:
> On Thu, Jul 09, 2020 at 10:02:36AM +0800, Liu Ying wrote:
> > It doesn't hurt to add the bridge in the global bridge list also
> > for
> > platform specific dw-hdmi drivers which are based on the component
> > framework.  This can be achieved by moving the drm_bridge_add()
> > function
> > call from dw_hdmi_probe() to __dw_hdmi_probe().  A counterpart
> > movement
> > for drm_bridge_remove() is also needed then.  Moreover, since
> > drm_bridge_add()
> > initializes &bridge->hpd_mutex, this may help those platform
> > specific
> > dw-hdmi drivers(based on the component framework) avoid accessing
> > the
> > uninitialized mutex in drm_bridge_hpd_notify() which is called in
> > dw_hdmi_irq().  Putting drm_bridge_add() in __dw_hdmi_probe() just
> > before
> > it returns successfully should bring no logic change for platforms
> > based
> > on the DRM bridge API, which is a good choice from safety point of
> > view.
> > Also, __dw_hdmi_probe() is renamed to dw_hdmi_probe() since
> > dw_hdmi_probe()
> > does nothing else but calling __dw_hdmi_probe().  Similar renaming
> > applies
> > to the __dw_hdmi_remove()/dw_hdmi_remove() pair.
> 
> Hmm, it took me some attempts to read this.
> Anyway, applied as-is to drm-misc-next.

Thank you, Sam.

Liu Ying

> 
> 	Sam
> 
> > 
> > Fixes: ec971aaa6775 ("drm: bridge: dw-hdmi: Make connector creation
> > optional")
> > Cc: Andrzej Hajda <a.hajda at samsung.com>
> > Cc: Neil Armstrong <narmstrong at baylibre.com>
> > Cc: Laurent Pinchart <Laurent.pinchart at ideasonboard.com>
> > Cc: Jonas Karlman <jonas at kwiboo.se>
> > Cc: Jernej Skrabec <jernej.skrabec at siol.net>
> > Cc: David Airlie <airlied at linux.ie>
> > Cc: Daniel Vetter <daniel at ffwll.ch>
> > Cc: Boris Brezillon <boris.brezillon at collabora.com>
> > Cc: Jerome Brunet <jbrunet at baylibre.com>
> > Cc: Cheng-Yi Chiang <cychiang at chromium.org>
> > Cc: Dariusz Marcinkiewicz <darekm at google.com>
> > Cc: Archit Taneja <architt at codeaurora.org>
> > Cc: Jose Abreu <joabreu at synopsys.com>
> > Cc: Sam Ravnborg <sam at ravnborg.org>
> > Cc: dri-devel at lists.freedesktop.org
> > Cc: NXP Linux Team <linux-imx at nxp.com>
> > Signed-off-by: Liu Ying <victor.liu at nxp.com>
> > ---
> > v1->v2:
> > * Put drm_bridge_add() in __dw_hdmi_probe() just before it returns
> >   successfully so that the bridge shows up in the global bridge
> > list
> >   late enough to avoid potential race condition with other display
> >   drivers. (Laurent)
> > * Rename __dw_hdmi_probe/remove() to dw_hdmi_probe/remove()
> >   respectively. (Laurent)
> > * Cc'ed Sam.
> > 
> >  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 44 +++++++++--------
> > --------------
> >  1 file changed, 13 insertions(+), 31 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > index 137b6eb..748df1c 100644
> > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > @@ -3179,9 +3179,11 @@ static void dw_hdmi_init_hw(struct dw_hdmi
> > *hdmi)
> >  		hdmi->phy.ops->setup_hpd(hdmi, hdmi->phy.data);
> >  }
> >  
> > -static struct dw_hdmi *
> > -__dw_hdmi_probe(struct platform_device *pdev,
> > -		const struct dw_hdmi_plat_data *plat_data)
> > +/* -------------------------------------------------------------
> > ----------------
> > + * Probe/remove API, used from platforms based on the DRM bridge
> > API.
> > + */
> > +struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev,
> > +			      const struct dw_hdmi_plat_data
> > *plat_data)
> >  {
> >  	struct device *dev = &pdev->dev;
> >  	struct device_node *np = dev->of_node;
> > @@ -3438,6 +3440,8 @@ __dw_hdmi_probe(struct platform_device *pdev,
> >  		hdmi->cec = platform_device_register_full(&pdevinfo);
> >  	}
> >  
> > +	drm_bridge_add(&hdmi->bridge);
> > +
> >  	return hdmi;
> >  
> >  err_iahb:
> > @@ -3451,9 +3455,12 @@ __dw_hdmi_probe(struct platform_device
> > *pdev,
> >  
> >  	return ERR_PTR(ret);
> >  }
> > +EXPORT_SYMBOL_GPL(dw_hdmi_probe);
> >  
> > -static void __dw_hdmi_remove(struct dw_hdmi *hdmi)
> > +void dw_hdmi_remove(struct dw_hdmi *hdmi)
> >  {
> > +	drm_bridge_remove(&hdmi->bridge);
> > +
> >  	if (hdmi->audio && !IS_ERR(hdmi->audio))
> >  		platform_device_unregister(hdmi->audio);
> >  	if (!IS_ERR(hdmi->cec))
> > @@ -3472,31 +3479,6 @@ static void __dw_hdmi_remove(struct dw_hdmi
> > *hdmi)
> >  	else
> >  		i2c_put_adapter(hdmi->ddc);
> >  }
> > -
> > -/* -------------------------------------------------------------
> > ----------------
> > - * Probe/remove API, used from platforms based on the DRM bridge
> > API.
> > - */
> > -struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev,
> > -			      const struct dw_hdmi_plat_data
> > *plat_data)
> > -{
> > -	struct dw_hdmi *hdmi;
> > -
> > -	hdmi = __dw_hdmi_probe(pdev, plat_data);
> > -	if (IS_ERR(hdmi))
> > -		return hdmi;
> > -
> > -	drm_bridge_add(&hdmi->bridge);
> > -
> > -	return hdmi;
> > -}
> > -EXPORT_SYMBOL_GPL(dw_hdmi_probe);
> > -
> > -void dw_hdmi_remove(struct dw_hdmi *hdmi)
> > -{
> > -	drm_bridge_remove(&hdmi->bridge);
> > -
> > -	__dw_hdmi_remove(hdmi);
> > -}
> >  EXPORT_SYMBOL_GPL(dw_hdmi_remove);
> >  
> >  /* -------------------------------------------------------------
> > ----------------
> > @@ -3509,7 +3491,7 @@ struct dw_hdmi *dw_hdmi_bind(struct
> > platform_device *pdev,
> >  	struct dw_hdmi *hdmi;
> >  	int ret;
> >  
> > -	hdmi = __dw_hdmi_probe(pdev, plat_data);
> > +	hdmi = dw_hdmi_probe(pdev, plat_data);
> >  	if (IS_ERR(hdmi))
> >  		return hdmi;
> >  
> > @@ -3526,7 +3508,7 @@ EXPORT_SYMBOL_GPL(dw_hdmi_bind);
> >  
> >  void dw_hdmi_unbind(struct dw_hdmi *hdmi)
> >  {
> > -	__dw_hdmi_remove(hdmi);
> > +	dw_hdmi_remove(hdmi);
> >  }
> >  EXPORT_SYMBOL_GPL(dw_hdmi_unbind);
> >  
> > -- 
> > 2.7.4
> > 
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel at lists.freedesktop.org
> > 
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