2014-11-21 Inki Dae <inki.dae@xxxxxxxxxxx>: > On 2014년 11월 21일 08:12, Gustavo Padovan wrote: > > 2014-11-13 Inki Dae <inki.dae@xxxxxxxxxxx>: > > > >> This patch fixes null pointer dereference issue incurred > >> when ipp driver is enabled and Exynos drm driver is closed. > >> > >> Non kms driver should register its own sub driver to setup necessary > >> resources, which is done by load(). So null pointer dereference > >> occurs when ipp driver is enabled and Exynos drm driver is closed > >> because ipp core device is registered after component_master_add_with_match > >> call. > >> > >> This patch makes exynos_drm_device_subdrv_probe() to be called after all non > >> kms drivers are registered. > > > > This patch is breaking exynos initialization, exynos_drm_device_subdrv_probe() > > needs the drvdata but it is still NULL at this point which make the whole > > exynos init fails. The drvdata is only set in exynos_drm_load() so we need > > call exynos_drm_device_subdrv_probe() after that. > > There might be my missing point but with this patch, > exynos_drm_device_subdrv_probe() will be called after exynos_drm_load() > call because all kms drivers are probed before > component_master_add_with_match call so exynos_drm_load() must be called > by component_master_add_with_match function before > exynos_drm_device_subdrv_probe call. > > So could you show me the error messages you faced with? There might be a > corner case I missed. I've added some debug output to it. It fails on exynos_drm_device_subdrv_probe() because the drvdata is NULL. I've added debug output to exynos_drm_load() and as you can see it doesn't get called before subdrv_probe(). I'm testing this on snow. [ 1.767835] [drm] Initialized drm 1.1.0 20060810 [ 1.771120] [drm:exynos_drm_init] [ 1.774774] [drm:exynos_drm_platform_probe] [ 1.778760] platform exynos-drm: Driver exynos-drm requests probe deferral [ 1.786178] platform 145b0000.dp-controller: Driver exynos-dp requests probe deferral [ 1.794374] exynos-drm-ipp exynos-drm-ipp: drm ipp registered successfully. [ 1.800372] [drm:exynos_drm_device_subdrv_probe] dev (null) Gustavo -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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