From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio Date: Thu, 02 Feb 2017 18:07:15 +0100 Message-ID: References: <20170202170307.24484-1-tiwai@suse.de> <20170202170307.24484-3-tiwai@suse.de> 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 (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id EC4C02676F6 for ; Thu, 2 Feb 2017 18:07:15 +0100 (CET) In-Reply-To: <20170202170307.24484-3-tiwai@suse.de> 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: alsa-devel@alsa-project.org Cc: Pierre-Louis Bossart , Jerome Anand List-Id: alsa-devel@alsa-project.org On Thu, 02 Feb 2017 18:02:15 +0100, Takashi Iwai wrote: > > The audio chicken bit (register offset 0x62f38) seems required to make > DP audio working on some machines. At least, on Dell Wyse 3040, I > failed to get the audio unless this bit is set once. > > Strangely, the bit seems necessary only once, and it persists after > that, even some power-off cycles. The register is supposedly > write-only, so it's no evidence whether the bit keeps effect > persistently. But, judging from the experiment, it looks enough to > set it up once at the device initialization. > > The patch is basically a cut from the original patch by Pierre-Louis > Bossart. > > Cc: Pierre-Louis Bossart > Signed-off-by: Takashi Iwai Sorry, this one is just a resend by mistake (I forgot to clean up while sending the other patch series). Please disregard. Takashi