Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:50465 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753490Ab1BDAbT (ORCPT ); Thu, 3 Feb 2011 19:31:19 -0500 MIME-Version: 1.0 In-Reply-To: References: <201102032009.17100.rjw@sisk.pl> From: Linus Torvalds Date: Thu, 3 Feb 2011 16:30:56 -0800 Message-ID: Subject: Re: 2.6.38-rc3-git1: Reported regressions 2.6.36 -> 2.6.37 To: Dave Airlie Cc: Carlos Mafra , Keith Packard , Dave Airlie , "Rafael J. Wysocki" , Takashi Iwai , Linux Kernel Mailing List , Maciej Rutecki , Florian Mickler , Andrew Morton , Kernel Testers List , Network Development , Linux ACPI , Linux PM List , Linux SCSI List , Linux Wireless List , DRI Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, Feb 3, 2011 at 4:06 PM, Dave Airlie wrote: > > If we are setting a mode on a connector it automatically will end up > in a DPMS on state, > so this seemed correct from what I can see. The more I look at that function, the more I disagree with you and with that patch. The code is just crazy. First off, it isn't even necessarily setting a mode to begin with, because as far as I can tell. If the mode doesn't change, neither mode_changed nor fb_changed will be true, afaik. There seems to be a fair amount of code there explicitly to avoid changing modes if not necessary. But even _if_ we are setting a mode, if I read the code correctly, the mode may be set to NULL - which seems to mean "turn it off". In which case it looks to me that drm_helper_disable_unused_functions() will actually do a (*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF); call on the crtc in question. So then blindly just saying "it's mode DRM_MODE_DPMS_ON" afterwards looks rather bogus to me. _Maybe_ it would work if it was done before that whole "disable_unused" logic. Or maybe it should just be done in drm_crtc_helper_set_mode(), which is what actually sets the mode (but there's the 'fb_changed' case too) > A future mode set shouldn't ever not turn the connector on, since > modesetting is an implicit > DPMS, > > It sounds like something more subtle than that, though I'm happy to > revert this for now, and let Keith > think about it a bit more. So I haven't heard anything from Keith. Keith? Just revert it? Or do you have a patch for people to try? Linus