From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: [PATCH] ALSA: hda - add AZX_DCAPS_I915_POWERWELL to Baytrail Date: Tue, 21 Apr 2015 11:48:52 +0200 Message-ID: References: <5536188B.0@canonical.com> Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.suse.de (cantor2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id D096A26069D for ; Tue, 21 Apr 2015 11:48:52 +0200 (CEST) In-Reply-To: <5536188B.0@canonical.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: David Henningsson Cc: mengdong.lin@intel.com, alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org At Tue, 21 Apr 2015 11:29:47 +0200, David Henningsson wrote: > > Hi, > > Baytrail is very much released and out there already - should this patch > also go to stable? I thought of that, but this patch also has a drawback, thus I hesitated to make it blindly. > Are there current problems (like HDMI codec not being detected) that are > fixed by this patch? If there is a known bug (report) and this fixes indeed, it deserves the stable kernel, indeed. Takashi > // David > > On 2015-04-21 07:12, mengdong.lin@intel.com wrote: > > From: Mengdong Lin > > > > This patch addes AZX_DCAPS_I915_POWERWELL to BYT (Baytrail). > > > > Like Braswell and Skylake, the HDMI codec on Bytrail is also in the shared > > power well with GPU. This power well must be turned on before we reset link > > to probe the codec, to avoid communication failure with the codec. > > > > The side effect is that this power is always ON in S0 because the BYT HDMI > > codec does not support EPSS or D3ClkStop and so the controller doesn't enter > > D3 at runtime, and the HDMI codec and analog codec share a single physical > > HD-A link and so we cannot reset the HD-A link freely when we re-enable the > > power to use the HDMI codec. > > > > Next step is to test if an AGP reset or double AGP reset on BYT HDMI codec is > > okay to bring the HDMI codec back to a functional state after restoring the > > power. If okay, we can bind the power on/off with the HDMI codec PM without > > interrupting the analog audio. > > > > Signed-off-by: Mengdong Lin > > > > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c > > index e1c2105..34040d2 100644 > > --- a/sound/pci/hda/hda_intel.c > > +++ b/sound/pci/hda/hda_intel.c > > @@ -297,6 +297,9 @@ enum { > > AZX_DCAPS_PM_RUNTIME | AZX_DCAPS_I915_POWERWELL |\ > > AZX_DCAPS_SNOOP_TYPE(SCH)) > > > > +#define AZX_DCAPS_INTEL_BAYTRAIL \ > > + (AZX_DCAPS_INTEL_PCH_NOPM | AZX_DCAPS_I915_POWERWELL) > > + > > #define AZX_DCAPS_INTEL_BRASWELL \ > > (AZX_DCAPS_INTEL_PCH | AZX_DCAPS_I915_POWERWELL) > > > > @@ -1992,7 +1995,7 @@ static const struct pci_device_id azx_ids[] = { > > .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH_NOPM }, > > /* BayTrail */ > > { PCI_DEVICE(0x8086, 0x0f04), > > - .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_INTEL_PCH_NOPM }, > > + .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_INTEL_BAYTRAIL }, > > /* Braswell */ > > { PCI_DEVICE(0x8086, 0x2284), > > .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_INTEL_BRASWELL }, > > > > -- > David Henningsson, Canonical Ltd. > https://launchpad.net/~diwic >