Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1165724AbdDXGot (ORCPT ); Mon, 24 Apr 2017 02:44:49 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:41649 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1165559AbdDXGok (ORCPT ); Mon, 24 Apr 2017 02:44:40 -0400 Subject: Re: [PATCH v2 2/2] drm: dw-hdmi: gate audio clock from the I2S enablement callbacks To: Archit Taneja , David Airlie References: <20170414083113.4255-1-romain.perier@collabora.com> <20170414083113.4255-3-romain.perier@collabora.com> Cc: dri-devel@lists.freedesktop.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Jose Abreu , Russell King , Neil Armstrong From: Romain Perier Message-ID: Date: Mon, 24 Apr 2017 08:44:34 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2287 Lines: 75 Hello, Le 19/04/2017 ? 06:51, Archit Taneja a ?crit : > > > On 04/14/2017 02:01 PM, Romain Perier wrote: >> Currently, the audio sampler clock is enabled from dw_hdmi_setup() at >> step E. and is kept enabled for later use. This clock should be enabled >> and disabled along with the actual audio stream and not always on (that >> is bad for PM). Futhermore, as described by the datasheet, the I2S > > s/Futhermore/Furthermore > >> variant need to gate/ungate the clock when the stream is > > s/need/needs > >> enabled/disabled. >> >> This commit adds a parameter to hdmi_audio_enable_clk() that controls >> when the audio sample clock must be enabled or disabled. Then, it adds >> the call to this function from dw_hdmi_i2s_audio_enable() and >> dw_hdmi_i2s_audio_disable(). >> >> Signed-off-by: Romain Perier >> --- >> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 20 ++++++++++++++------ >> 1 file changed, 14 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> index 5b328c0..a6da634 100644 >> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> @@ -544,6 +544,12 @@ void dw_hdmi_set_sample_rate(struct dw_hdmi >> *hdmi, unsigned int rate) >> } >> EXPORT_SYMBOL_GPL(dw_hdmi_set_sample_rate); >> >> +static void hdmi_enable_audio_clk(struct dw_hdmi *hdmi, bool enable) >> +{ >> + hdmi_modb(hdmi, enable ? 0 : HDMI_MC_CLKDIS_AUDCLK_DISABLE, >> + HDMI_MC_CLKDIS_AUDCLK_DISABLE, HDMI_MC_CLKDIS); >> +} >> + >> void dw_hdmi_ahb_audio_enable(struct dw_hdmi *hdmi) >> { >> hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n); >> @@ -557,6 +563,12 @@ void dw_hdmi_ahb_audio_disable(struct dw_hdmi >> *hdmi) >> void dw_hdmi_i2s_audio_enable(struct dw_hdmi *hdmi) >> { >> hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n); >> + hdmi_enable_audio_clk(hdmi, true); >> +} >> + >> +void dw_hdmi_i2s_audio_disable(struct dw_hdmi *hdmi) >> +{ >> + hdmi_enable_audio_clk(hdmi, false); >> } > > This should be static too. > > If you're okay with the suggestions, I can fix these myself and push. Let > me know if that's okay. > > Thanks, > Archit > Yes, I completely agree. Thanks, Romain