From mboxrd@z Thu Jan 1 00:00:00 1970 From: yong.wu@mediatek.com (Yong Wu) Date: Wed, 20 Jul 2016 11:02:00 +0800 Subject: [PATCH 2/3] drm/mediatek: Add probe-defer for MTK IOMMU and SMI In-Reply-To: <1468983721-3627-1-git-send-email-yong.wu@mediatek.com> References: <1468983721-3627-1-git-send-email-yong.wu@mediatek.com> Message-ID: <1468983721-3627-2-git-send-email-yong.wu@mediatek.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org If DRM begin to probe before SMI probe done. It will hang: [ 7.832359] Call trace: [ 7.834778] [] mtk_smi_larb_get+0x24/0xa8 [ 7.840300] [] mtk_drm_crtc_enable+0x6c/0x450 Use the new interface(mtk_smi_larb_is_ready) to wait for IOMMU and SMI probe done. Signed-off-by: Yong Wu --- drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c index 3970fcf..3ef3124 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c @@ -21,6 +21,7 @@ #include #include #include +#include #include "mtk_drm_drv.h" #include "mtk_drm_plane.h" #include "mtk_drm_ddp_comp.h" @@ -201,6 +202,10 @@ int mtk_ddp_comp_init(struct device *dev, struct device_node *node, } of_node_put(larb_node); + /* Wait until MTK IOMMU and SMI probe done.*/ + if (!mtk_smi_larb_is_ready(&larb_pdev->dev)) + return -EPROBE_DEFER; + comp->larb_dev = &larb_pdev->dev; return 0; -- 1.8.1.1.dirty