From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 39FBE1A0BE0; Mon, 27 Jul 2026 03:08:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785121734; cv=none; b=fV6AjJEIUk562V0C0oVBwxJq4iOnJPqNlbT5wR5lrcQrI3qTN8fhl9Uwomp33yrO6V3G82J+o6JydD9GXC/rabSBPaZisZde6+UxW1EVyE9v9gy3KPWsk3ZrzlSw8JWAc2u8kMVfU9a5Pj455er8aT06wox5JH/9Y+1fAoQEUqA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785121734; c=relaxed/simple; bh=6QHp3/ubXQwK+p2GpvX7O+6/lmsAW5FR4tAQM7WYA94=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rT35+qng0EXhKs7uSHP1owOrCxIdALWL8SgfxkIp4UiTOUpt0QcoxSSSzbk2oX6qHe0Kr5ziyuTL2KU25S0lF6bg/RvNtcQmFEAoz4R5Kp0eUfVqUzHWMSyOBZ3ol5uzbFJhBDRL4isqEVO3cGBU/kMrQE0sFjcBFSfiDqAIeq4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IcwSeqsE; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IcwSeqsE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB72D1F000E9; Mon, 27 Jul 2026 03:08:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785121732; bh=fS7ymxv3eEPwNc/r1Xxde8ivyrvBC/eS2NCy79nNj9g=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=IcwSeqsEpzJKdv8f+gczfLzAssZMPOYMwKZEz/9sKo4/YRx5Oer1IOFoAdXF2htIP ml2g3EPRCyqefUmJYrcLmILmuukHVWfzHW1IcSU/x7L+NQ/a8ZY/KoRDD+1hxpiUoR TKC1Q/kL2vIIccw3qTgudVk3/+/MxkZJlgtxyoazV6z4riLz7LYVHgS/WHO6lUseNb nqGs182nHsulCjM8XxGS/CU053xrlocKZCuLVzoQUk0lSp5toiDzGDaV9cdthky818 4DDmhmAQxShQiOiRxORBDh69OpYO66yGiPUU9D/DnoWLwAVOwRBc0ZfvgGQlJ2anIX IEeeL1PEuagcA== Date: Sun, 26 Jul 2026 22:08:49 -0500 From: Bjorn Andersson To: Val Packett Cc: Konrad Dybcio , Neil Armstrong , Abel Vesa , Stephan Gerhold , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, usb4-upstream@oss.qualcomm.com, Raghavendra Thoorpu , Konrad Dybcio Subject: Re: [PATCH] soc: qcom: pmic_glink: Avoid losing early rpmsg probe Message-ID: References: <20260720-topic-pmic_glink_defer-v1-1-94c0f233f2f7@oss.qualcomm.com> <9843990f-a7cf-419c-9abc-2351aa6ca6ea@packett.cool> 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=us-ascii Content-Disposition: inline In-Reply-To: <9843990f-a7cf-419c-9abc-2351aa6ca6ea@packett.cool> On Sun, Jul 26, 2026 at 12:11:48AM -0300, Val Packett wrote: > > On 7/20/26 11:39 AM, Konrad Dybcio wrote: > > From: Konrad Dybcio > > > > The PMIC GLINK rpmsg device can appear before the platform device has > > finished probing. In that case pmic_glink_rpmsg_probe() sees > > __pmic_glink as NULL and returns -ENODEV, which is treated as a fatal > > probe failure for the rpmsg endpoint. > > > > If this race is hit, pg->ept is never installed and PMIC GLINK clients > > never receive the service-up notification. This may leave the system > > with no Type-C functionality and without battery/power supply > > management. > > > > Return -EPROBE_DEFER when the rpmsg endpoint arrives before the platform > > device is ready. [..] > > Hm, in the Linaro tree there was this hack patch to accomplish the same > thing differently: > > https://gitlab.com/Linaro/arm64-laptops/linux/-/commit/8c309c7e852a49118ddc2ee54c3d8b7c74466f6a > > that claimed that "Returning -EPROBE_DEFER from the rpmsg driver does not > seem to work because the rpmsg core doesn't handle EPROBE_DEFER(?)" > > Was that resolved or was that always wrong? > Returning an error from probe of an rpmsg driver will destroy the "endpoint", which results in the GLINK channel being closed again. (See rpmsg_dev_probe()) This is still on the todo list to figure out how to gracefully handle. Regards, Bjorn > > Thanks, > ~val >