Hi, On Mon, Mar 7, 2016 at 12:37 AM, Mark yao <mark....@rock-chips.com> wrote: > On 2016年03月05日 20:39, Russell King - ARM Linux wrote: >> >> On Sat, Mar 05, 2016 at 12:11:16PM +0000, John Keeping wrote: >>> >>> On Fri, Mar 04, 2016 at 03:22:01PM -0800, Douglas Anderson wrote: >>>> >>>> The drm_encoder_cleanup() was missing both from the error path of >>>> dw_hdmi_rockchip_bind(). This caused a crash when slub_debug was >>>> enabled and we ended up deferring probe of HDMI at boot. >>>> >>>> This call isn't needed from unbind() because if dw_hdmi_bind() returns >>>> no error then it takes over the job of freeing the encoder (in >>>> dw_hdmi_unbind). >>>> >>>> Signed-off-by: Douglas Anderson <diand...@chromium.org> >>>> --- >>> >>> Does dw_hdmi-imx need a similar change? I wonder if it would be cleaner >>> to push this into dw_hdmi_bind() if it affects all of the platforms.. >> >> I don't think moving it there would make sense - keep the initialisation >> and cleanup together in the same file so that it's contained together. >> > > I don't like this patch too, initialisation and cleanup not in the same file > looks bad, > > How about: > > drivers/gpu/drm/bridge/dw-hdmi.c > void dw_hdmi_unbind(struct device *dev, struct device *master, void *data) > hdmi_writeb(hdmi, ~0, HDMI_IH_MUTE_PHY_STAT0); > > hdmi->connector.funcs->destroy(&hdmi->connector); > - hdmi->encoder->funcs->destroy(hdmi->encoder); > > drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c > static int dw_hdmi_rockchip_bind(struct device *dev, struct device *master, > > - return dw_hdmi_bind(dev, master, data, encoder, iores, irq, > plat_data); > + ret = dw_hdmi_bind(dev, master, data, encoder, iores, irq, > plat_data); > + if (ret) > + drm_encoder_cleanup(encoder); > + > + return ret; > } > > static void dw_hdmi_rockchip_unbind(struct device *dev, struct device > *master, > void *data) > { > + drm_encoder_cleanup(...); > return dw_hdmi_unbind(dev, master, data); > }
That'a a reasonable suggestion in theory. ...but we run into the same problem I've run into before with the strange relationship between dw_hdmi and its descendants. Specifically: * "struct dw_hdmi", which has a pointer to encoder, is private to dw-hdmi.c * We could get the encoder if we had a pointer to the "struct rockchip_hdmi", but there's no way to get that. You would _think_ you could get it back using platform_get_drvdata() because it was stashed with platform_set_drvdata(). ...but you'd be wrong. The platform_set_drvdata() is just there to fool you. I believe when you call dw_hdmi_bind() it clobbers your drvdata when it calls dev_set_drvdata(dev, hdmi); Said another way: taking your suggestion means we need to add some way for dw_hdmi-rockchip.c to get a pointer to the encoder from a "struct device". We could (A) move the "struct dw_hdmi" definition to a private header and allow dw_hdmi-rockchip.c to include it or we could (B) add a dw_hdmi_get_encoder() API call that dw_hdmi-rockchip.c could call. If someone would let me know whether (A) or (B) is OK I'm happy to post a patch. ...or, of course, if I've made a mistake in all the above, feel free to point it out. -Doug