From patchwork Thu Feb 2 10:12:53 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Takashi Iwai X-Patchwork-Id: 9551545 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BD3CD60453 for ; Thu, 2 Feb 2017 10:13:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B7ADA28425 for ; Thu, 2 Feb 2017 10:13:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AA15328433; Thu, 2 Feb 2017 10:13:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A993127F82 for ; Thu, 2 Feb 2017 10:13:03 +0000 (UTC) Received: from alsa0.perex.cz (localhost [127.0.0.1]) by alsa0.perex.cz (Postfix) with ESMTP id 76B7C267549; Thu, 2 Feb 2017 11:13:01 +0100 (CET) X-Original-To: alsa-devel@alsa-project.org Delivered-To: alsa-devel@alsa-project.org Received: by alsa0.perex.cz (Postfix, from userid 1000) id 5311F267550; Thu, 2 Feb 2017 11:12:59 +0100 (CET) Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id 4E103266E00 for ; Thu, 2 Feb 2017 11:12:57 +0100 (CET) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 6FB38AB9A; Thu, 2 Feb 2017 10:12:56 +0000 (UTC) From: Takashi Iwai To: alsa-devel@alsa-project.org, ntel-gfx@lists.freedesktop.org Date: Thu, 2 Feb 2017 11:12:53 +0100 Message-Id: <20170202101253.11093-1-tiwai@suse.de> X-Mailer: git-send-email 2.11.0 Cc: Pierre-Louis Bossart , Jani Nikula , rakesh.a.ughreja@intel.com, Jerome Anand , Daniel Vetter , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Subject: [alsa-devel] [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Reviewed-by: Ville Syrjälä --- drivers/gpu/drm/i915/i915_reg.h | 3 +++ drivers/gpu/drm/i915/intel_lpe_audio.c | 7 +++++++ 2 files changed, 10 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 4e24ba0cdbe8..4f15a3dc6d98 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -2062,6 +2062,9 @@ enum skl_disp_power_wells { #define I915_HDMI_LPE_AUDIO_SIZE 0x1000 /* DisplayPort Audio w/ LPE */ +#define VLV_AUD_CHICKEN_BIT_REG _MMIO(VLV_DISPLAY_BASE + 0x62F38) +#define VLV_CHICKEN_BIT_DBG_ENABLE (1 << 0) + #define _VLV_AUD_PORT_EN_B_DBG (VLV_DISPLAY_BASE + 0x62F20) #define _VLV_AUD_PORT_EN_C_DBG (VLV_DISPLAY_BASE + 0x62F30) #define _VLV_AUD_PORT_EN_D_DBG (VLV_DISPLAY_BASE + 0x62F34) diff --git a/drivers/gpu/drm/i915/intel_lpe_audio.c b/drivers/gpu/drm/i915/intel_lpe_audio.c index d3ffe0012692..3ba2799e93bd 100644 --- a/drivers/gpu/drm/i915/intel_lpe_audio.c +++ b/drivers/gpu/drm/i915/intel_lpe_audio.c @@ -248,6 +248,13 @@ static int lpe_audio_setup(struct drm_i915_private *dev_priv) goto err_free_irq; } + /* enable chicken bit; at least this is required for Dell Wyse 3040 + * with DP outputs (but only sometimes by some reason!) + */ + I915_WRITE(VLV_AUD_CHICKEN_BIT_REG, + I915_READ(VLV_AUD_CHICKEN_BIT_REG) | + VLV_CHICKEN_BIT_DBG_ENABLE); + return 0; err_free_irq: irq_free_desc(dev_priv->lpe_audio.irq);