From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from cstnet.cn (smtp21.cstnet.cn [159.226.251.21]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A5A303EBF18; Sun, 25 Jan 2026 13:03:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.21 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769346183; cv=none; b=twQHslSgkeqn9QZtQhTLhwg0KiC/D54xzlSGAQPGO8hwK+g7z4TlWQbU9rZDfDcq9DEiOOGKWxBNS1OKEKwy23HHdbkaZC2xgVp4iYlLkiHcw20wvIs5X3XVs/R29U3okQBT9GUo5q/cP2oJQcftbicQt12IdC/D1ZtNA7Ryn58= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769346183; c=relaxed/simple; bh=xtre1dUDUYZ4Q/Evoopq2aLMZmm8uOX3MPShwyhMd3s=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rvvzKizf8Z11Qf/hlVAKrlBHjWebQY7A7W+aSNBjEiHkPB79OTOycxTerqt6vJqz1owA33XXIGfuSGqCdEj2jSQINW3y93Oo+MigH5JItCEmGMMQNYBxm0iPdEWwB7DmECz9jgSmirvf/3fz1eZRTW7yfKgkL/imBYI3F4+dfjk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.21 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from [192.168.0.107] (unknown [123.118.222.47]) by APP-01 (Coremail) with SMTP id qwCowACH825yFHZpgUgsBg--.19908S2; Sun, 25 Jan 2026 21:02:43 +0800 (CST) Message-ID: Date: Sun, 25 Jan 2026 21:02:42 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 0/4] regulator: spacemit-p1: Fix voltage ranges and support board power tree To: Yixun Lan , Guodong Xu Cc: Liam Girdwood , Mark Brown , Alex Elder , Lee Jones , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Troy Mitchell , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, spacemit@lists.linux.dev, devicetree@vger.kernel.org References: <20260124-spacemit-p1-v2-0-2c86b06694ba@riscstar.com> <76bd53dd-0ca9-4358-a0b6-a49283e43c5f@iscas.ac.cn> <20260125110333-GYD71302@gentoo.org> Content-Language: en-US From: Vivian Wang In-Reply-To: <20260125110333-GYD71302@gentoo.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-CM-TRANSID:qwCowACH825yFHZpgUgsBg--.19908S2 X-Coremail-Antispam: 1UD129KBjvJXoWxCw1kGrWxArWfJrWrKF4DArb_yoW5Gr18pa 9Ika9rKFWkKr4fZwnFkw1IyayFy397Jw45W345Kw15Gr90vF1agF1UK3yY9Fy3Gr4kCw42 yrWUKas3JF90v3DanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvqb7Iv0xC_Kw4lb4IE77IF4wAFF20E14v26ryj6rWUM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rw A2F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Gr0_Xr1l84ACjcxK6xII jxv20xvEc7CjxVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4 A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IE w4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMc vjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvEwIxGrwACI402YVCY1x02628vn2kIc2xKxwCY 1x0262kKe7AKxVW8ZVWrXwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8Jw C20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAF wI0_GFv_WrylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjx v20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2 jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0x ZFpf9x07bIBTOUUUUU= X-CM-SenderInfo: pzdqw2pxlnt03j6l2u1dvotugofq/ On 1/25/26 19:03, Yixun Lan wrote: > Hi Guodong, > > On 12:27 Sun 25 Jan , Guodong Xu wrote: >> On Sun, Jan 25, 2026 at 12:18 PM Guodong Xu wrote: >>> On Sat, Jan 24, 2026 at 2:25 PM Vivian Wang wrote: >>>> >>>> On 1/24/26 08:20, Guodong Xu wrote: >>>>> [...] >>>>> >>>>> Note: Patch 3 introduces a bisect breakage by transitioning to >>>>> pin-specific supply names. Probe failures will occur on existing boards >>>>> until Patch 4 updates the corresponding DTS file. >>>> Ouch, that's not a bisect breakage, that's an *ABI breakage*. And AFAICT >>>> this is still not okay in 2026, >>>> see Documentation/devicetree/bindings/ABI.rst >>>> >>>> So the bindings would need to be changed to accept both the new and old way. >>> Ideally yes. However, considering this ABI change's actual effect, the two >>> K1 boards (BPI-F3 and Jupiter) in the kernel get their power settings >>> from boot firmware as well, and the types of peripherals enabled in the .dts >>> files are very limited, the probe failure of the pmic regulator doesn't >>> affect much. So, I think this breakage is acceptable. >>> >>>> Driver-wise, at a cursory look from someone not familiar with the >>>> regulator stuff, maybe we can make it compatible with old DTS by adding >>>> the new names as aliases ({devm_,}regulator_register_supply_alias?) as >>>> "vin" or "buck5", if we see the old vin-supply definitions? >>>> >>> We can do that of course. My hesitation is, however, it makes the driver take >>> extra code which may not be needed once all .dts files have been updated. The >>> driver code will be left there forever. >>> >> Mark gave his opinion in v1 review [1], please allow me to partially quote >> here: "(it's an ABI change so shouldn't really happen, but perhaps there are >> few enough users for everyone to coordinate and it's what you all prefer)." >> >> I do expect to collect more ideas before I decide whether and what to do in >> v3, or maybe v3 is not required. >> > As I checked the dts tree (DT queued for v6.20), although we introduced the > regulator of P1/PMIC, but there is no consumers so far, so in real life, we > shouldn't break anything. In this case, I'd suggest we just give up for doing > the ABI backward compatible work which should simplify our life.. Having checked again, I agree that this is not that big of a problem. The breakage with old DT is limited to an otherwise harmless error on boot that doesn't affect functionality since there are no users. Vivian "dramforever" Wang.