From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 68C9E242D89; Mon, 4 Aug 2025 08:51:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754297505; cv=none; b=JTVkWtHyOPK7PnxRs9Fe8U54WX3u7id5rmfhaKjPVga5/oe+YIkYDvO28BK6v3J9J9EfztNCar1Jv4LUSDE9fFppfElVXL/r1uOuTd2lku9uhkMS5IQLlM28iap6JDc13Md6DdCurPWI6otYpB5rDpctDeGBOOPxeZdwhWmjX2c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754297505; c=relaxed/simple; bh=6BVLxWZDI6oTK0aU1mKaqp/Pgk0nOrw3tsRdbFp16HI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=osK1YhNuzFbrJG87XafrSVPP+PFo6/Rwja2cND53sCwdcHCtQVnfzzae5YnMQNsU9/mdXOr6OG1+AzeBhvxrsrEpdTykHO/dvnQSTBb5dMDCSWmXcCUJ9z9J8cBaKKwxpCAdUMVMu3gwzYC38F7w7UG51MEvnOuuCvR2Kh8o6Ko= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=C3D7OXgi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="C3D7OXgi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3A78C4CEE7; Mon, 4 Aug 2025 08:51:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754297504; bh=6BVLxWZDI6oTK0aU1mKaqp/Pgk0nOrw3tsRdbFp16HI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=C3D7OXgiMHabUt/rRD2FtPPdy8d8FouZqA+W80TuQoGYUBZ1DezjM2p0AZgo7NtZw ioz6HXkBw0633CzdgZ9w35jdE/5S/Dgo8Dg/eYnCGCo0bJQBzZAAGMsDhDas3GqEaB Sb+gwC0dGyh1Vf+ve7cqOXEGTLKrNOL6gWWY/XR+xesiLNfgp62ejlorSjANpdwkq1 M8QW3/8Q6lxxjY4st1QPVAywKJPkkPXqKlzPkRWuzSkbldqMQy/FtiPQXdRheeKgOP 8nNdQ6cRH9nANNGYHPNHcwPHCipgUjuJIW7lW/GHgLLIVXKyZlhcdVZtK3OLyQR4vJ YF0JFPVUT6tUg== Message-ID: <592e9a1e-a58f-435d-aff7-13c13fe0598a@kernel.org> Date: Mon, 4 Aug 2025 10:51:42 +0200 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mfd: intel_soc_pmic_chtdc_ti: Set use_single_read regmap_config flag To: Andy Shevchenko Cc: Lee Jones , Andy Shevchenko , linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20250804083419.205892-1-hansg@kernel.org> From: Hans de Goede Content-Language: en-US, nl In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Andy, On 4-Aug-25 10:47 AM, Andy Shevchenko wrote: > On Mon, Aug 4, 2025 at 10:34 AM Hans de Goede wrote: >> >> Testing has shown that reading multiple registers at once (for 10 bit >> adc values) does not work. Set the use_single_read regmap_config flag >> to make regmap split these for is. >> >> This should fix temperature opregion accesses done by >> drivers/acpi/pmic/intel_pmic_chtdc_ti.c and is also necessary for >> the upcoming drivers for the ADC and battery MFD cells. > > ... > >> + /* Reading multiple registers at once is not supported */ >> + .use_single_read = true, > > By HW or by problem in regmap as being suggested here: > https://lore.kernel.org/linux-gpio/CALNFmy1ZRqHz6_DD_2qamm-iLQ51AOFQH=ahCWRN7SAk3pfZ_A@mail.gmail.com/ > ? This is a hw limitation. I tried with i2ctransfer to directly access the chip and it returns invalid values (1) after the first byte read. > As a quick fix I am fine with this. > Reviewed-by: Andy Shevchenko Thank you. Regards, Hans 1) I don't remember if it was 0, 0xff or repeating of the first byte. But it definitely did not work.