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 585C5346E4A; Thu, 14 May 2026 21:38:13 +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=1778794693; cv=none; b=BhNOYw1W1u7T+X5sjFH6yNwHGB7WtQghlbn+PsiH/nRO/vMht/tM63DKiKYuXxMR6J8v/zdUNFFvgBJj6ucDfcZaAQSnFMrYPPRlMJxJ8vbEljU7ft21xb62hs9YnA6aFWfGiksCgHRtIi7Itx4xH9zE5KxzxJhP/XHIxOrWN5w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778794693; c=relaxed/simple; bh=+ToJqHQD+rEElJLal/LDAFQwHkZ0hsRrOg1Da/O/BWo=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=eS9f8UXTN6epUaySYSWLP8KcVgrhaGk74hrHM0/Xu96gmX4JNCC6zXSQVzFuWeEFPiba6FFec4ePPIDtT9jfFVwz1Ng7WzczQy5Nw+NvBsYTFeUJtMKmX3Vuwmjq/RUD87UqFj/8I9XsHCqGqtRCT1YyYE7KiiX8C84PBWi7aAc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qadKqpMJ; 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="qadKqpMJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3807C2BCB3; Thu, 14 May 2026 21:38:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778794693; bh=+ToJqHQD+rEElJLal/LDAFQwHkZ0hsRrOg1Da/O/BWo=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=qadKqpMJ7C5igbh17379B2UBnXmlTYdpGEicDRtuWOLr7XI0Anhf6B8c6ZOo/Y7Zo FXzPerAJCz8a6lNOvZTowS/hZ3vOv0kK1rrbvKXIrw0RNxaQs/ub5Wegd9W3oepLB+ AeYfzFnY4uFu/ZpilNNzLjDsf67rq5iiAni97T7rY3TqbbgbKAKX7ygX3Q9/A/NwFx NXtoDJ3X1Uf/DokJYtI+2TV9NnXkkllGl7z7ibLrqc5RTCSneccivIrUqDoJi7cVgz dTfBIFZNLund5c/IRDjuL8uL4SQCTqhYZUWkU/OGewoQKTrInba7UIqup+4qZ7liva MwOs5/llK/A6A== Date: Thu, 14 May 2026 16:38:11 -0500 From: Bjorn Helgaas To: sashiko-reviews@lists.linux.dev Cc: linux-pci@vger.kernel.org, "Rafael J . Wysocki" , Lukas Wunner , Marco Nenciarini , Michal Winiarski , Ilpo Jarvinen , Eric Chanudet , Jean Guyader , Alex Williamson , Sinan Kaya , Mario Limonciello , Mika Westerberg , linux-kernel@vger.kernel.org, Bjorn Helgaas Subject: Re: [PATCH v1] PCI: Wait for device readiness after D3hot -> D0uninitialized transition Message-ID: <20260514213811.GA434353@bhelgaas> Precedence: bulk X-Mailing-List: linux-pci@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: <20260514200625.C6877C2BCB3@smtp.kernel.org> On Thu, May 14, 2026 at 08:06:25PM +0000, sashiko-bot@kernel.org wrote: > Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: > - [High] Ignored return value of `pci_dev_wait()` masks hardware readiness timeouts > -- > > commit 606c3a6294de4df52ee7dc27a7792cef6c8f72c4 > Author: Bjorn Helgaas > > PCI: Wait for device readiness after D3hot -> D0uninitialized transition > > This commit adds a call to pci_dev_wait() after transitioning a device from > D3hot to D0uninitialized. This ensures the device is ready to accept config > accesses, especially for devices with No_Soft_Reset == 0. > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > index 8f7cfcc000901..9d0fc9fbb76a0 100644 > > --- a/drivers/pci/pci.c > > +++ b/drivers/pci/pci.c > [ ... ] > > @@ -1341,10 +1351,14 @@ int pci_power_up(struct pci_dev *dev) > > pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, 0); > > > > /* Mandatory transition delays; see PCI PM 1.2. */ > > - if (state == PCI_D3hot) > > + if (state == PCI_D3hot) { > > pci_dev_d3_sleep(dev); > > - else if (state == PCI_D2) > > + if (!(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) > > + pci_dev_wait(dev, "power up D3hot->D0uninitialized", > > + PCIE_RESET_READY_POLL_MS); > > Is it safe to ignore the return value of pci_dev_wait() here? > > If the device times out or disconnects, pci_dev_wait() returns -ENOTTY. By > ignoring this error, pci_power_up() continues, unconditionally sets > dev->current_state = PCI_D0, and can return success (1 for need_restore). > > If pci_power_up() returns success, will callers like pci_back_from_sleep() > execute pci_restore_state() against an unresponsive device, which could > potentially trigger PCIe Master Aborts, AER events, or system crashes? > > Should pci_power_up() propagate the error from pci_dev_wait() to prevent > this? Good point. I think it should look like this instead: if (state == PCI_D3hot) { pci_dev_d3_sleep(dev); if (!(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) { ret = pci_dev_wait(dev, "power up D3hot->D0uninitialized", PCIE_RESET_READY_POLL_MS); if (ret) { pci_err(dev, "Not ready after soft reset\n"); dev->current_state = PCI_D3cold; return -EIO; } } } else if (state == PCI_D2) { udelay(PCI_PM_D2_DELAY); } > > + } else if (state == PCI_D2) { > > udelay(PCI_PM_D2_DELAY); > > + } > > > > end: > > dev->current_state = PCI_D0; > > -- > Sashiko AI review ยท https://sashiko.dev/#/patchset/20260514153124.404060-1-bhelgaas@google.com?part=1