Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934463AbdDGRPi (ORCPT ); Fri, 7 Apr 2017 13:15:38 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:52826 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933961AbdDGRPT (ORCPT ); Fri, 7 Apr 2017 13:15:19 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 44D0860CF0 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=architt@codeaurora.org Subject: Re: [PATCH] drm: dw-hdmi: Implement the mode_fixup drm helper To: Romain Perier , daniel.vetter@ffwll.ch References: <20170407121743.4142-1-romain.perier@collabora.com> Cc: David Airlie , linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org From: Archit Taneja Message-ID: Date: Fri, 7 Apr 2017 22:45:12 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170407121743.4142-1-romain.perier@collabora.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2588 Lines: 75 Hi, On 4/7/2017 5:47 PM, Romain Perier wrote: > This helper is supposed to validate or reject the modeline before it > applied by the mode setting. Currently this function has been dropped, > it was previously set to a dummy function that always returned true. For > both cases, this means that userspace can ask for a bad modeline that > will be always accepted. > > On some platforms, like Rockchip, the drm dw_hdmi-rockchip variant driver > already implements the atomic_check drm helper, so mode_fixup cannot be > handled and implemented there (as drm_atomic_helper relies on either > atomic_check or mode_fixup). > > This commit implements this helper. It only checks that this mode is > correct from the connector point of view We do have a atomic_check op in drm_connector_helper_funcs. I've rarely seen it being used, but it could be used to validate the mode w.r.t the connector, rather than checking it in the bridge's mode_fixup op. Daniel, Is it okay to use the connector's atomic_check to validate a mode. (by peeping into the new_crtc_state->mode?) Thanks, Archit > > Signed-off-by: Romain Perier > --- > drivers/gpu/drm/bridge/dw-hdmi.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c b/drivers/gpu/drm/bridge/dw-hdmi.c > index 22211ff..3bd0807 100644 > --- a/drivers/gpu/drm/bridge/dw-hdmi.c > +++ b/drivers/gpu/drm/bridge/dw-hdmi.c > @@ -1740,6 +1740,21 @@ static int dw_hdmi_bridge_attach(struct drm_bridge *bridge) > return 0; > } > > + > +static bool dw_hdmi_bridge_mode_fixup(struct drm_bridge *bridge, > + const struct drm_display_mode *orig_mode, > + struct drm_display_mode *mode) > +{ > + struct dw_hdmi *hdmi = bridge->driver_private; > + struct drm_connector *connector = &hdmi->connector; > + enum drm_mode_status status; > + > + status = dw_hdmi_connector_mode_valid(connector, mode); > + if (status != MODE_OK) > + return false; > + return true; > +} > + > static void dw_hdmi_bridge_mode_set(struct drm_bridge *bridge, > struct drm_display_mode *orig_mode, > struct drm_display_mode *mode) > @@ -1781,6 +1796,7 @@ static const struct drm_bridge_funcs dw_hdmi_bridge_funcs = { > .enable = dw_hdmi_bridge_enable, > .disable = dw_hdmi_bridge_disable, > .mode_set = dw_hdmi_bridge_mode_set, > + .mode_fixup = dw_hdmi_bridge_mode_fixup, > }; > > static irqreturn_t dw_hdmi_i2c_irq(struct dw_hdmi *hdmi) > -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation