From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sai Prakash Ranjan Subject: Re: [PATCH] drm/msm/disp/dpu: Use proper define for drm_encoder_init() 'encoder_type' Date: Fri, 17 Aug 2018 14:36:19 +0530 Message-ID: References: <20180816233616.148248-1-swboyd@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180816233616.148248-1-swboyd@chromium.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Stephen Boyd , Rob Clark Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, Jeykumar Sankaran , Jordan Crouse , Sean Paul List-Id: linux-arm-msm@vger.kernel.org On 8/17/2018 5:06 AM, Stephen Boyd wrote: > We got a bug report that this function oopses when trying to do a kasprintf(). > > PC is at string+0x2c/0x60 > LR is at vsnprintf+0x28c/0x4ec > pc : [] lr : [] pstate: a0c00049 > sp : ffffff80095fb540 > x29: ffffff80095fb540 x28: ffffff8008ad42bc > x27: 00000000ffffffd8 x26: 0000000000000000 > x25: ffffff8008c216c8 x24: 0000000000000000 > x23: 0000000000000000 x22: ffffff80095fb720 > x21: 0000000000000000 x20: ffffff80095fb720 > x19: ffffff80095fb6f0 x18: 000000000000000a > x17: 00000000b42ba473 x16: ffffff800805bbe8 > x15: 00000000000a157d x14: 000000000000000c > x13: 0000000000000000 x12: 0000ffff0000000f > x11: 0000000000000003 x10: 0000000000000001 > x9 : 0000000000000040 x8 : 000000000000001c > x7 : ffffffffffffffff x6 : 0000000000000000 > x5 : 0000000000000228 x4 : 0000000000000000 > x3 : ffff0a00ffffff04 x2 : 0000000000007961 > x1 : 0000000000000000 x0 : 0000000000000000 > Process kworker/3:1 (pid: 61, stack limit = 0xffffff80095f8000) > Call trace: > Exception stack(0xffffff80095fb400 to 0xffffff80095fb540) > b400: 0000000000000000 0000000000000000 0000000000007961 ffff0a00ffffff04 > b420: 0000000000000000 0000000000000228 0000000000000000 ffffffffffffffff > b440: 000000000000001c 0000000000000040 0000000000000001 0000000000000003 > b460: 0000ffff0000000f 0000000000000000 000000000000000c 00000000000a157d > b480: ffffff800805bbe8 00000000b42ba473 000000000000000a ffffff80095fb6f0 > b4a0: ffffff80095fb720 0000000000000000 ffffff80095fb720 0000000000000000 > b4c0: 0000000000000000 ffffff8008c216c8 0000000000000000 00000000ffffffd8 > b4e0: ffffff8008ad42bc ffffff80095fb540 ffffff80088d5fc4 ffffff80095fb540 > b500: ffffff80088d35d8 00000000a0c00049 ffffff80095fb550 ffffff80080d06a4 > b520: ffffffffffffffff ffffff80088d5e0c ffffff80095fb540 ffffff80088d35d8 > [] string+0x2c/0x60 > [] vsnprintf+0x28c/0x4ec > [] kvasprintf+0x68/0x100 > [] kasprintf+0x60/0x80 > [] drm_encoder_init+0x134/0x164 > [] dpu_encoder_init+0x60/0x94 > [] _dpu_kms_drm_obj_init+0xa0/0x424 > [] dpu_kms_hw_init+0x61c/0x6bc > [] msm_drm_bind+0x380/0x67c > [] try_to_bring_up_master+0x228/0x264 > [] component_master_add_with_match+0x90/0xc0 > [] msm_pdev_probe+0x260/0x2c8 > [] platform_drv_probe+0x58/0xa8 > [] driver_probe_device+0x2d8/0x40c > [] __device_attach_driver+0xd4/0x10c > [] bus_for_each_drv+0xb4/0xd0 > [] __device_attach+0xd0/0x160 > [] device_initial_probe+0x24/0x30 > [] bus_probe_device+0x38/0x98 > [] deferred_probe_work_func+0x144/0x148 > [] process_one_work+0x218/0x3bc > [] process_scheduled_works+0x44/0x48 > [] worker_thread+0x288/0x32c > [] kthread+0x134/0x13c > [] ret_from_fork+0x10/0x18 > Code: 910003fd 2a0403e6 eb0400ff 54000060 (38646845) > > Looking at the code I see that drm_encoder_init() is called from the DPU > code with 'DRM_MODE_CONNECTOR_DSI' passed in as the 'encoder_type' > argument (follow from _dpu_kms_initialize_dsi()). That corresponds to > the integer 16. That is then indexed into drm_encoder_enum_list in > drm_encoder_init() to look up the name of the encoder. If you're still > following along, that's an encoder not a connector! We really want to > use DRM_MODE_ENCODER_DSI (integer 6) instead of DRM_MODE_CONNECTOR_DSI > here, or we'll go out of bounds of the encoder array. Pass the right > thing and everything is fine. > > Cc: Jeykumar Sankaran > Cc: Jordan Crouse > Cc: Sean Paul > Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support") > Signed-off-by: Stephen Boyd > --- > drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c > index 7dd6bd2d6d37..74cc204b07e8 100644 > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c > @@ -450,7 +450,7 @@ static void _dpu_kms_initialize_dsi(struct drm_device *dev, > int i, rc; > > /*TODO: Support two independent DSI connectors */ > - encoder = dpu_encoder_init(dev, DRM_MODE_CONNECTOR_DSI); > + encoder = dpu_encoder_init(dev, DRM_MODE_ENCODER_DSI); > if (IS_ERR_OR_NULL(encoder)) { > DPU_ERROR("encoder init failed for dsi display\n"); > return; > I have tested this on sdm845 mtp and it does fix the issue. Tested-by: Sai Prakash Ranjan