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 5D7EF107A4; Fri, 15 Dec 2023 07:50:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="vNrcWIPF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF90BC433C7; Fri, 15 Dec 2023 07:50:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1702626635; bh=vbor0/x22PNu3gqlwMMEYKNlzreoR29T2zrYtNDm+o8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vNrcWIPFK81LdUvYkAvK3OXRcr0rv6R0UunNq23hDRlD087FCNlakv959X2MsvnQS 80YVslQkp57pnuAj3B6M0UU6fZ+aZzctt3U398gRKxNPurKsPu7hYK0a2bgt624dZn SHCOoLuWK5Y43Oj4b9mNamaPaxr2AVoktXxz8NdPgZagn6o4pjPQXfvBoGYhsbSmbO cUZ4l/PzS5mge5JtJvG1yv5ox/nLDywbUy2wifezM0B++QKXnyPyggjVP+Xllc6Cqf ti5EV/7Vjcg9gHH7tS0XBT/nX1WTHSDDzgkXrBtB18lFaH+k6rf3ee2H95r1iRk9Bl aTW+BIoEXmjBQ== Received: from johan by xi.lan with local (Exim 4.96.2) (envelope-from ) id 1rE2xq-0006BT-2N; Fri, 15 Dec 2023 08:50:30 +0100 Date: Fri, 15 Dec 2023 08:50:30 +0100 From: Johan Hovold To: Rob Clark Cc: Dmitry Baryshkov , linux-arm-msm@vger.kernel.org, Rob Clark , Andy Gross , Bjorn Andersson , Konrad Dybcio , open list Subject: Re: [PATCH] soc: qcom: pmic_glink: Fix boot when QRTR=m Message-ID: References: <20231213210644.8702-1-robdclark@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Thu, Dec 14, 2023 at 12:44:10PM -0800, Rob Clark wrote: > On Thu, Dec 14, 2023 at 8:08 AM Johan Hovold wrote: > > > > On Thu, Dec 14, 2023 at 04:38:35PM +0100, Johan Hovold wrote: > > > > > I took a closer look at this and indeed we do have code that triggers a > > > reprobe of a device in case there was a successful probe while the > > > device was probing. > > > > > > This was introduced by commit 58b116bce136 ("drivercore: deferral race > > > condition fix") and the workaround for the reprobe-loop bug that hack > > > led to is to not return -EPROBE_DEFER after registering child devices as > > > no one managed to come up with a proper fix. This was documented here: > > > > > > fbc35b45f9f6 ("Add documentation on meaning of -EPROBE_DEFER") > > > > > > But please spell this out in some more detail in the commit message, and > > > add a Fixes and CC stable tag. > > > > And please update the commit summary as I've been booting with QRTR=m > > all along just fine. I guess the issue is if you have pmic_glink > > built-in or in the initramfs but forgot to include qrtr or similar? > > I do have both QRTR=m and QCOM_GLINK=m. I'm honestly not sure what > started triggering this issue for me.. it seemed to have started after > merging msm-next + drm-misc-next on top of your > jhovold/wip/sc8280xp-v6.7-rc5 (the merged branches were based on -rc3 > so this shouldn't have really brought in random non-drm things). > Maybe there is a timing element to it? Yeah, possibly, and device links may also come into play here. > I felt like the problem was obvious enough, and the exact details of > why I started hitting this were not important enough to spend time > tracking down. The patch itself is of course fine itself as a clean up (or microoptimisation) but the claim that it solves, and is the correct fix for, a probe loop issue is not obvious at all and requires some further justification. Since he last time someone suggested reverting the commit that introduced the probe-loop issue, the result was to leave things as they were and just document the workaround, it should be fine to just refer to that commit: fbc35b45f9f6 ("Add documentation on meaning of -EPROBE_DEFER") Perhaps you can keep the Subject if you make it clear in the commit message that this bug isn't always hit with QRTR=m. Johan