From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757443AbcAOKRf (ORCPT ); Fri, 15 Jan 2016 05:17:35 -0500 Received: from mail-wm0-f66.google.com ([74.125.82.66]:34664 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751915AbcAOKR3 (ORCPT ); Fri, 15 Jan 2016 05:17:29 -0500 Date: Fri, 15 Jan 2016 11:17:30 +0100 From: Daniel Vetter To: Laurent Pinchart Cc: Maxime Ripard , Mike Turquette , Stephen Boyd , David Airlie , Thierry Reding , Philipp Zabel , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-sunxi@googlegroups.com, Chen-Yu Tsai , Hans de Goede , Alexander Kaplan , Boris Brezillon , Wynter Woods , Thomas Petazzoni , Rob Clark , Daniel Vetter Subject: Re: [PATCH v2 13/26] drm/fb_cma_helper: Remove implicit call to disable_unused_functions Message-ID: <20160115101730.GH19130@phenom.ffwll.local> Mail-Followup-To: Laurent Pinchart , Maxime Ripard , Mike Turquette , Stephen Boyd , David Airlie , Thierry Reding , Philipp Zabel , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-sunxi@googlegroups.com, Chen-Yu Tsai , Hans de Goede , Alexander Kaplan , Boris Brezillon , Wynter Woods , Thomas Petazzoni , Rob Clark References: <1452785109-6172-1-git-send-email-maxime.ripard@free-electrons.com> <1452785109-6172-14-git-send-email-maxime.ripard@free-electrons.com> <2014724.QmjXVju9UW@avalon> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2014724.QmjXVju9UW@avalon> X-Operating-System: Linux phenom 4.3.0-1-amd64 User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 15, 2016 at 01:13:05AM +0200, Laurent Pinchart wrote: > Hi Maxime, > > Thank you for the patch. > > On Thursday 14 January 2016 16:24:56 Maxime Ripard wrote: > > The drm_fbdev_cma_init function always calls the > > drm_helper_disable_unused_functions. Since it's part of the usual probe > > process, all the drivers using that helper will end up having their encoder > > and CRTC disable functions called at probe if their device has not been > > reported as enabled. > > > > This could be fixed by reading out from the registers the current state of > > the device if it is enabled, but even that will not handle the case where > > the device is actually disabled. > > > > Moreover, the drivers using the atomic modesetting expect that their enable > > and disable callback to be called when the device is already enabled or > > disabled (respectively). > > > > We can however fix this issue by moving the call to > > drm_helper_disable_unused_functions out of drm_fbdev_cma_init and make the > > drivers needing it (all the drivers calling drm_fbdev_cma_init and not > > using the atomic modesetting) explicitly call it. > > I'd rather add it to all drivers that call drm_fbdev_cma_init(). All the > atomic ones must have special code to cope with it that could be rendered > useless by the removal of the drm_helper_disable_unused_functions() call. That > code should be removed too, and it would be easier to check drivers one by one > and fixing them individually (outside of this patch series, unless you insist > ;-)) when removing the explicit drm_helper_disable_unused_functions() call. I had the same thought, but figured there's really no good reason ever to do this. I suspect most of that disable_unused_function stuff we have all over is supreme cargo-cult anyway ;-) > Other than that the patch looks fine to me. So went ahead and applied to drm-misc. -Daniel > > > Signed-off-by: Maxime Ripard > > --- > > drivers/gpu/drm/drm_fb_cma_helper.c | 3 --- > > drivers/gpu/drm/imx/imx-drm-core.c | 1 + > > drivers/gpu/drm/sti/sti_drv.c | 1 + > > drivers/gpu/drm/tilcdc/tilcdc_drv.c | 1 + > > 4 files changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c > > b/drivers/gpu/drm/drm_fb_cma_helper.c index c19a62561183..daa98d881142 > > 100644 > > --- a/drivers/gpu/drm/drm_fb_cma_helper.c > > +++ b/drivers/gpu/drm/drm_fb_cma_helper.c > > @@ -348,9 +348,6 @@ struct drm_fbdev_cma *drm_fbdev_cma_init(struct > > drm_device *dev, > > > > } > > > > - /* disable all the possible outputs/crtcs before entering KMS mode */ > > - drm_helper_disable_unused_functions(dev); > > - > > ret = drm_fb_helper_initial_config(helper, preferred_bpp); > > if (ret < 0) { > > dev_err(dev->dev, "Failed to set initial hw configuration.\n"); > > diff --git a/drivers/gpu/drm/imx/imx-drm-core.c > > b/drivers/gpu/drm/imx/imx-drm-core.c index 7b990b4e96d2..e1db57791fc9 > > 100644 > > --- a/drivers/gpu/drm/imx/imx-drm-core.c > > +++ b/drivers/gpu/drm/imx/imx-drm-core.c > > @@ -312,6 +312,7 @@ static int imx_drm_driver_load(struct drm_device *drm, > > unsigned long flags) dev_warn(drm->dev, "Invalid legacyfb_depth. > > Defaulting to 16bpp\n"); legacyfb_depth = 16; > > } > > + drm_helper_disable_unused_functions(drm); > > imxdrm->fbhelper = drm_fbdev_cma_init(drm, legacyfb_depth, > > drm->mode_config.num_crtc, MAX_CRTC); > > if (IS_ERR(imxdrm->fbhelper)) { > > diff --git a/drivers/gpu/drm/sti/sti_drv.c b/drivers/gpu/drm/sti/sti_drv.c > > index 1469987949d8..506b5626f3ed 100644 > > --- a/drivers/gpu/drm/sti/sti_drv.c > > +++ b/drivers/gpu/drm/sti/sti_drv.c > > @@ -160,6 +160,7 @@ static int sti_load(struct drm_device *dev, unsigned > > long flags) > > > > drm_mode_config_reset(dev); > > > > + drm_helper_disable_unused_functions(dev); > > drm_fbdev_cma_init(dev, 32, > > dev->mode_config.num_crtc, > > dev->mode_config.num_connector); > > diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c > > b/drivers/gpu/drm/tilcdc/tilcdc_drv.c index 876cad58b1f9..24be31d69701 > > 100644 > > --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c > > +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c > > @@ -294,6 +294,7 @@ static int tilcdc_load(struct drm_device *dev, unsigned > > long flags) break; > > } > > > > + drm_helper_disable_unused_functions(dev); > > priv->fbdev = drm_fbdev_cma_init(dev, bpp, > > dev->mode_config.num_crtc, > > dev->mode_config.num_connector); > > -- > Regards, > > Laurent Pinchart > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch