Messages in this thread | | | Date | Thu, 29 Aug 2013 20:31:14 +0200 | From | Sascha Hauer <> | Subject | Re: [PATCH v2] imx-drm: Fix probe failure |
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On Thu, Aug 29, 2013 at 05:21:30PM +0200, Daniel Vetter wrote: > On Thu, Aug 29, 2013 at 10:59:22AM -0300, Fabio Estevam wrote: > > Since commit b5dc0d10 (drm/imx: kill firstopen callback) the following probe > > failure is seen: > > > > [drm] Supports vblank timestamp caching Rev 1 (10.10.2010). > > [drm] No driver support for vblank timestamp query. > > [drm] Initialized imx-drm 1.0.0 20120507 on minor 0 > > imx-ldb ldb.10: adding encoder failed with -16 > > imx-ldb: probe of ldb.10 failed with error -16 > > imx-ipuv3 2400000.ipu: IPUv3H probed > > imx-ipuv3 2800000.ipu: IPUv3H probed > > imx-ipuv3-crtc imx-ipuv3-crtc.0: adding crtc failed with -16. > > imx-ipuv3-crtc: probe of imx-ipuv3-crtc.0 failed with error -16 > > imx-ipuv3-crtc imx-ipuv3-crtc.1: adding crtc failed with -16. > > imx-ipuv3-crtc: probe of imx-ipuv3-crtc.1 failed with error -16 > > imx-ipuv3-crtc imx-ipuv3-crtc.2: adding crtc failed with -16. > > imx-ipuv3-crtc: probe of imx-ipuv3-crtc.2 failed with error -16 > > imx-ipuv3-crtc imx-ipuv3-crtc.3: adding crtc failed with -16. > > imx-ipuv3-crtc: probe of imx-ipuv3-crtc.3 failed with error -16 > > > > The reason for the probe failure is that now 'imxdrm->references' is incremented > > early in imx_drm_driver_load(), so the following checks in imx_drm_add_crtc() > > and imx_drm_add_encoder(): > > > > if (imxdrm->references) { > > ret = -EBUSY; > > goto err_busy; > > } > > > > ,will always fail. > > > > Let the drm core handle the references instead of doing this manually in > > imx-drm. In imx-drm-core the open and close callbacks map to drm_open and > > drm_close, which handle the references via open_count. > > > > After this patch, lvds panel is functional on a mx6qsabrelite board. > > > > Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> > > Yeah, just ripping out the imxdrm->references stuff will restore imx, but > of course all the funny races are still fundamentally there. So we still > rely on userspace being really careful to obey the right module loading > sequence and not start any drm client before that has all completed. So > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > > Greg, when you slurp this in can you pls also add the imx todo entry from > the other thread? > > http://www.mail-archive.com/dri-devel@lists.freedesktop.org/msg43698.html
You said there:
> +- Fix up the driver load sequence to make sure all submodules for encoders/crtcs > + are fully loaded before the drm driver is registered.
We can't know when all submodules are registered and really I think this is not necessary. The driver will use the components available during open time. When being opened no components will be registered/deregistered. So a user will always get a functional drm device with the components he actually loaded.
Sascha
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