From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-08.mail-europe.com (mail-08.mail-europe.com [57.129.93.249]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 54C732737F3; Sat, 18 Oct 2025 03:43:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=57.129.93.249 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760759042; cv=none; b=unGGxIlyjaRL0eB5Yn3JJC8mmv+M3Q7Ps7zhywjwHyVt4d9Qx63yAw12+nnldsMfuGmYaK1RtWYqQh2os3eHvjpxc6N1Wnmp+4soMU2HKzoMLCsQ3pMovAxToT1WrpzowNejPV38D4CksfqUiF/35Tu2Dx2rbole5ozApGSLiuE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760759042; c=relaxed/simple; bh=QUvK43uEdjp4VgrEbeSeV/3sAkcsewJcyFAAteaMPL8=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=MAS6Gnm1ZhUo4sBpKpcleGrFRtL2e6f4murtWcMK866E/O/yhmwS1Id0JWgiPcJ2I+fxvqcOF/3C6jz4UZ9HLR5LoG3nHCq+6zQuDRzpJ55JkANtOe4DnK/HDR4YECswl72rVO2zB2RfY9aVwFgkidDBAa+H9nthM9JTupVtmnI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=joelselvaraj.com; spf=pass smtp.mailfrom=joelselvaraj.com; dkim=pass (2048-bit key) header.d=joelselvaraj.com header.i=@joelselvaraj.com header.b=MYBKEFOT; arc=none smtp.client-ip=57.129.93.249 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=joelselvaraj.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=joelselvaraj.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=joelselvaraj.com header.i=@joelselvaraj.com header.b="MYBKEFOT" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelselvaraj.com; s=protonmail3; t=1760759024; x=1761018224; bh=QUvK43uEdjp4VgrEbeSeV/3sAkcsewJcyFAAteaMPL8=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector; b=MYBKEFOTulr7k4atKLGtbTazwgyQyOzwgxJNoO5VPW1L8mlcfNXOsRBI3EKeGxeAC X6pjklk0eWWFemYdVQgkvgcUcGfa8ks6Gtk/KaLltGGznvVi2dJxfu+fPbO1qifQ1I rvabCdNzC8izkTuuleXrmUBNB2e6YZ5+NoioC5HycjWuYWnCiUr+jIr+aiFsjTXwDs w9jGhO0bdCBnswuseFXUkxivmaCiTV/yzUldp0hbrxFP0c68LOiOtn58+SVcuVMcpz SlVn0zmr9SAUlEEvCq5yQ1q2uH2girHmImKuDDidsVw3bleOTxxH9+zFiUpgLaInU7 2OxRqVO61r5vQ== Date: Sat, 18 Oct 2025 03:43:39 +0000 To: Konrad Dybcio , Bjorn Andersson , Konrad Dybcio , Rob Herring , Krzysztof Kozlowski , Conor Dooley From: Joel Selvaraj Cc: linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64: dts: qcom: sdm845-shift-axolotl: fix touchscreen properties Message-ID: <2a014801-e1ef-47fa-b067-9b566b9d523e@joelselvaraj.com> In-Reply-To: <8fd387f5-5b4c-48ea-aa3e-f453ddd5b159@oss.qualcomm.com> References: <20250919-shift-axolotl-fix-touchscreen-dts-v1-1-60e26ad4e038@joelselvaraj.com> <8a5eecdd-d80f-4955-8ab7-cf6fd991a3b7@oss.qualcomm.com> <267eb29d-b506-43df-9380-3d79798c772c@joelselvaraj.com> <8fd387f5-5b4c-48ea-aa3e-f453ddd5b159@oss.qualcomm.com> Feedback-ID: 113812696:user:proton X-Pm-Message-ID: 265feb92edfb20b0e6fde8ba253ef90a0d453330 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hi Konrad Dybcio, On 10/17/25 4:57 AM, Konrad Dybcio wrote: >>> All the changes look good given your commit message, but you dropped >>> this wakeup-source property without explanation. It's fine to do so >>> if it's intended, but please mention it if so >> >> In reference to the touchscreen/edt-ft5x06.c driver which is used here, >> I am bit confused how wakeup-source works. Does specifying wakeup-source >> in dts automatically makes "device_may_wakeup(dev)" return true, even if >> device_init_wakeup is NOT configured in the driver? I noticed some >> drivers do: >> >> device_init_wakeup(dev,device_property_read_bool(dev, "wakeup-source")); >> >> but the edt-ft5x06 driver doesnt do the init, but directly checks for >> may_wakeup in suspend/resume. >> >> Few scenarios based on the driver code and my understanding: >> 1. if device_may_wakeup will return true when wakeup-source is >> specified, I probably want to just remove it, because irq and regulator >> is not disabled during suspend and this will likely cause power drain. >=20 > I think this may be the case >=20 >> 2. The driver has an option to specify wake-gpio. In which case, the >> touchscreen is put in some low power hibernate mode with irq and >> regulators still enabled. But the touchscreen controller used in this >> device doesn't seem to have support for a wake-gpio (atleast based on >> downstream code). So that is not an option. >=20 > IIRC Shift was pretty open about development collaboration.. maybe you > could reach out to them to confirm on schematics that the GPIO is > absent? >=20 >> 3. if device_may_wakeup will always return false since >> device_init_wakeup is not configured and since no wake-gpio is >> available, the irq and regulators will be disabled during suspend. >> Therefore, the device will not wake up from sleep even if wakeup-source >> is specified as the irq is not going to be triggered. >> >> So probably no point in specifying wakeup-source either way I think? But >> I am not sure which of these explanation is correct and thus not sure >> what to mention in the v2 patch commit message. Also, there is a >> possibility I am not understanding something. A little help from someone >> will be very nice and sorry if I am obviously missing something. >=20 > I think this is intended for things like double-tap-to-wake, which > obviously need some hw backing if you don't want to just keep the > touchscreen online at "full power" 24/7 >=20 Yeah. I think I will remove the wakeup-source for now to avoid potential=20 battery drain. Once I get more info on wake-gpio/low-power mode and test=20 with users that tap-to-wake work as expected, it will be added. For now,=20 this is not something expected to be working. Will send a v2 with=20 updated commit message. Thank you, Joel Selvaraj > Konrad