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 D613345C0B; Fri, 30 Aug 2024 15:34:08 +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=1725032048; cv=none; b=NxKDF6RTZNUA5k0Je1OBBamQQviiuNA7YQLLa5ENNyZICzwHaugGE78UNPqM3wc+ZhiDxPd/E0KK7N86/KriZx/IYR0gkuVK9tJW5MbMNXo6Z9znIhpl1cMkWhDSHcRNZuRAzw8enq4DIWe+Px1hCu/pHZCp0cAWKvnb0sfb9/w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725032048; c=relaxed/simple; bh=SnJjIE4aJi7goKoUT2vPrbpSERDXPoBU01P8N44zpQA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=EawfVmnnxkcZk4aWhpx8kc7YUQesIiMGpTgj24GipgzacME4zJHJ+hf2qty5m43EMQA76cbDQlpis+Gi0Ice87V3Hiir+ZULXi0pUZjj/ITxtoN/VZ5VAjlFjVDGKdcDWjWsoOMcKRJd1AnSrK20oJch0s9A2UuL0b4vMay76rs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aqGpU9gN; 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="aqGpU9gN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 388ACC4CEC2; Fri, 30 Aug 2024 15:32:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725032048; bh=SnJjIE4aJi7goKoUT2vPrbpSERDXPoBU01P8N44zpQA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=aqGpU9gND0Xkx2vgNd9t5Za4V97d9Cg8CYp6r3V1pI5XqBX+ryJTGfCYF393sgWMp udA35bMV+/RdjUSCmPILaQrP6QypMGkGC+euyaI4g424v8sG6ypwp0brztQhsqmyU6 3SFQz52gQWvXzyBlMVXkjYGhqkoA09zryH9UOuHTd88LxUwufiAWvt/a/NZuBJPxRh NoYh6oe8XulWJgdVcK6gOrL1g1L1eR1PSyfKz1A9TrPvHXxfqbxwdmf6pOGQ1Tj0Xw aXhzfEp8HUWWVLEvAMBBHyOUNUeBEG1RWsKWxypYCNAFCi91wekdFo3uBkA4Krafvk MKc0PyGl6E6cA== Message-ID: <08e8f26a-d87e-4d3e-9896-b809d5f0c3a0@kernel.org> Date: Fri, 30 Aug 2024 17:31:14 +0200 Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1] soc: qcom: pbs: Simplify with dev_err_probe() To: Dan Carpenter , Konrad Dybcio Cc: Krzysztof Kozlowski , Yu Jiaoliang , Bjorn Andersson , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, opensource.kernel@vivo.com References: <20240829124813.3264437-1-yujiaoliang@vivo.com> <894145dc-46fb-451f-a461-d0b9ff1e50dd@kernel.org> <10fad15b-d2a6-4ec1-8af7-bde8f7bf39be@kernel.org> <63162b67-22ef-482f-9600-861e9dbaf4fc@stanley.mountain> Content-Language: en-US From: Konrad Dybcio In-Reply-To: <63162b67-22ef-482f-9600-861e9dbaf4fc@stanley.mountain> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 30.08.2024 5:19 PM, Dan Carpenter wrote: > On Fri, Aug 30, 2024 at 12:03:20PM +0200, Konrad Dybcio wrote: >> On 30.08.2024 10:08 AM, Krzysztof Kozlowski wrote: >>> On 29/08/2024 14:48, Yu Jiaoliang wrote: >>>> Error handling in probe() can be a bit simpler with dev_err_probe(). >>>> >>>> Signed-off-by: Yu Jiaoliang >>>> --- >>>> drivers/soc/qcom/qcom-pbs.c | 7 +++---- >>>> 1 file changed, 3 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/drivers/soc/qcom/qcom-pbs.c b/drivers/soc/qcom/qcom-pbs.c >>>> index 77a70d3d0d0b..ab9de12ec901 100644 >>>> --- a/drivers/soc/qcom/qcom-pbs.c >>>> +++ b/drivers/soc/qcom/qcom-pbs.c >>>> @@ -201,10 +201,9 @@ static int qcom_pbs_probe(struct platform_device *pdev) >>>> } >>>> >>>> ret = device_property_read_u32(pbs->dev, "reg", &val); >>>> - if (ret < 0) { >>>> - dev_err(pbs->dev, "Couldn't find reg, ret = %d\n", ret); >>>> - return ret; >>>> - } >>>> + if (ret < 0) >>>> + return dev_err_probe(pbs->dev, ret, "Couldn't find reg\n"); >>> >>> This cannot defer, so not much benefits. And you ignore other place in >>> the probe()... That's like a weird pattern with all your patches change >>> something irrelevant, but leave other places unchanged. >>> >>> That's pointless and churn. >> >> Hm, that's a good point.. Maybe the static checker folks could come up >> with a way that would find functions that call something that can defer >> at one point or another and suggest (not) using dev_err_probe with W=1/2.. >> (although that is probably not going to be very high prio given all the >> other static checker issues we're still yet to resolve) >> >> Unless we have something like that already? +CC Dan > > I believe these patches are from people writing their own Coccinelle scripts to > do the conversions. There aren't any published scripts which care one way or > the other. > > device_property_read_u32() can't return -EPROBE_DEFER. It's documented in a > comment. So this is just a question of preferred style. There isn't a kernel > wide preferred style on this. Some maintainers prefer to not use dev_err_probe() > where it "doesn't make sense because ret isn't -EPROBE_DEFER". Other maintainers > use it all the time even for error code literals like: > return dev_err_probe(pbs->dev, -EINVAL, "invalid input.\n"); > Because "it's cleaner, more uniform and only takes one line". I think Julia > said she didn't want to get involved with this debate and I definitely don't. Personally, I don't mind either.. so longer as it's consistent within the file > > There are a few things which we could do: > > 1) Returning -EPROBE_DEFER to an ioctl or something besides a probe() > This is a bug right? -EPROBE_DEFER is basically kernel internal for probe() > functions. It tried to write this but it was complicated so I gave up. Maybe call_tree.pl can somehow be used with an if name[-5:] == "probe" or something along those lines.. > > 2) Printing an error message for -EPROBE_DEFER warnings > I've written this check and I can test it tonight. > > 3) Not propagating the -EPROBE_DEFER returns > This shouldn't be too hard to write. > > Let me add a KTODO in case anyone wants to do this before I get around to it. > > KTODO: write Smatch EPROBE_DEFER warnings Thanks! Konrad