From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com ([192.55.52.93]:11528 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750884AbdBTPBr (ORCPT ); Mon, 20 Feb 2017 10:01:47 -0500 From: Mika Kuoppala To: Chris Wilson Cc: intel-gfx@lists.freedesktop.org, stable@vger.kernel.org Subject: Re: [PATCH 6/7] drm/i915: Restart RPS using the same RP_CONTROL as from initialisation In-Reply-To: <20170220144744.GL11809@nuc-i3427.alporthouse.com> References: <20170220094713.22874-1-chris@chris-wilson.co.uk> <20170220094713.22874-6-chris@chris-wilson.co.uk> <87tw7pc4cw.fsf@gaia.fi.intel.com> <20170220144744.GL11809@nuc-i3427.alporthouse.com> Date: Mon, 20 Feb 2017 16:59:05 +0200 Message-ID: <87lgt0di2u.fsf@gaia.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: stable-owner@vger.kernel.org List-ID: Chris Wilson writes: > On Mon, Feb 20, 2017 at 04:40:47PM +0200, Mika Kuoppala wrote: >> Chris Wilson writes: >> >> > During initialisation, we set different flags for different >> > architectures - these should be preserved when we reload the RPS >> > thresholds. If we use a mmio read, it will first ensure that the >> > threshold registers are written before we apply the latch in RP_CONTROL. >> > >> > Signed-off-by: Chris Wilson >> > Cc: Mika Kuoppala >> > Cc: stable@vger.kernel.org >> >> This will change how the valleyview will do the DOWN_IDLE, >> due to readback you will get a GEN6_RP_DOWN_IDLE_CONT. > > No change, since we don't use it on byt - we only use the EI intervals > as we manually calculate the up/down signals based on the C0 counters. > >> I can't think of why we would like to keep that behaviour >> as the IDLE_CONT setup is a twart in my opinion. >> >> If you agree with the above, substitute the IDLE_CONT in >> valleview setup and you can add, > > It is a mistake in the setup, but that change has to be seperate to > exclude it as being part of the magic that avoids the hang. Ok, so let me rephrase. As the skipping of the IDLE_CONT had an effect to the way byt behaves, we intentionally want to keep that with byt. So this is no accident, and yes it makes sense Reviewed-by: Mika Kuoppala > -Chris > > -- > Chris Wilson, Intel Open Source Technology Centre