Messages in this thread | | | From | Heiko Stuebner <> | Subject | Re: [PATCH v3] drm/rockchip: Refactor the component match logic. | Date | Wed, 15 Mar 2017 18:23:27 +0100 |
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Am Mittwoch, 15. März 2017, 18:00:04 CET schrieb Heiko Stuebner: > Am Mittwoch, 15. März 2017, 18:20:47 CET schrieb Jeffy Chen: > > Currently we are adding all components from the dts, if one of their > > drivers been disabled, we would not be able to bring up others. > > > > Refactor component match logic, follow exynos drm. > > > > Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com> > > Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> > > This reliably produces null pointer dereference errors in > __platform_driver_register called from rockchip_drm_init > on at least rk3036 and rk3288 (probably more) when applied on top of > Linus' tree from today. Log attached and Rockchip drm compiled as module. > > I'm currently dug into other areas, so hadn't have time to investigate > further yet.
> +#define DRV_PTR(drv, cond) (IS_ENABLED(cond) ? &drv : NULL) > + > +static struct platform_driver *rockchip_drm_comp_drvs[] = { > + &vop_platform_driver, > + DRV_PTR(rockchip_dp_driver, CONFIG_ROCKCHIP_ANALOGIX_DP), > + DRV_PTR(cdn_dp_driver, CONFIG_ROCKCHIP_CDN_DP), > + DRV_PTR(dw_hdmi_rockchip_pltfm_driver, CONFIG_ROCKCHIP_DW_HDMI), > + DRV_PTR(dw_mipi_dsi_driver, CONFIG_ROCKCHIP_DW_MIPI_DSI), > + DRV_PTR(inno_hdmi_driver, CONFIG_ROCKCHIP_INNO_HDMI), > +};
[...]
> +static int rockchip_drm_register_drivers(void) > +{ > + int i, ret; > + > + for (i = 0; i < ARRAY_SIZE(rockchip_drm_comp_drvs); i++) { > + ret = platform_driver_register(rockchip_drm_comp_drvs[i]); > + if (ret) > + goto err_unreg; > + }
This of course won't work in the NULL case, as platform_driver_register always dereferences its parameter [0], so you should only call it for the actual non- null array elements - of course same for unregister.
Heiko
[0] http://lxr.free-electrons.com/source/drivers/base/platform.c#L617
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