From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre-Louis Bossart Subject: Re: [alsa-devel] [RFC PATCH 28/40] soundwire: intel: handle disabled links Date: Mon, 5 Aug 2019 14:18:35 -0500 Message-ID: <4c4e64fb-9657-0312-a19f-2a17b44fbae3@linux.intel.com> References: <20190725234032.21152-1-pierre-louis.bossart@linux.intel.com> <20190725234032.21152-29-pierre-louis.bossart@linux.intel.com> <20190805165729.GC24889@buildpc-HP-Z230> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190805165729.GC24889@buildpc-HP-Z230> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Sanyog Kale Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, tiwai@suse.de, broonie@kernel.org, vkoul@kernel.org, gregkh@linuxfoundation.org, jank@cadence.com, srinivas.kandagatla@linaro.org, slawomir.blauciak@intel.com List-Id: alsa-devel@alsa-project.org On 8/5/19 11:57 AM, Sanyog Kale wrote: > On Thu, Jul 25, 2019 at 06:40:20PM -0500, Pierre-Louis Bossart wrote: >> On most hardware platforms, SoundWire interfaces are pin-muxed with >> other interfaces (typically DMIC or I2S) and the status of each link >> needs to be checked at boot time. >> >> For Intel platforms, the BIOS provides a menu to enable/disable the >> links separately, and the information is provided to the OS with an >> Intel-specific _DSD property. The same capability will be added to >> revisions of the MIPI DisCo specification. [snip] >> diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h >> index c7dfc824be80..f78b076a8782 100644 >> --- a/include/linux/soundwire/sdw.h >> +++ b/include/linux/soundwire/sdw.h >> @@ -380,6 +380,7 @@ struct sdw_slave_prop { >> * @err_threshold: Number of times that software may retry sending a single >> * command >> * @mclk_freq: clock reference passed to SoundWire Master, in Hz. >> + * @hw_disabled: if true, the Master is not functional, typically due to pin-mux >> */ >> struct sdw_master_prop { >> u32 revision; >> @@ -395,6 +396,7 @@ struct sdw_master_prop { >> bool dynamic_frame; >> u32 err_threshold; >> u32 mclk_freq; >> + bool hw_disabled; > > Do we have such cases where some of SoundWire links are disabled and > some enabled? Yes, by default my ICL test board uses HDaudio for the codec so the SoundWire link0 is disabled. If I rework the board and change the BIOS advanced menu then SoundWire link0 is enabled. This information is dynamically provided to the OS after the _INI step. SoundWire-2/3 are used typically for attached DMICs or for a combination of SoundWire amplifier and mic capture. It's really platform-specific. > >> }; >> >> int sdw_master_read_prop(struct sdw_bus *bus); >> -- >> 2.20.1 >> >