Re: [PATCH v3] imx-drm: Fix probe failure

[Sascha Hauer <s.hauer@pengutronix.de>]

On Fri, Aug 30, 2013 at 02:53:12PM -0300, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam@freescale.com>
> 
> 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.
> 
> Instead of manually keeping the references in the imx-drm driver, let's use
> drm->open_count.
> 
> After this patch, lvds panel is functional on a mx6qsabrelite board.
> 
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
> ---
> This one should go via Dave Airlie's tree instead of Greg's tree because
> b5dc0d10 is in Dave's tree.

Acked-by: Sascha Hauer <s.hauer@pengutronix.de>

Sascha


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