From patchwork Wed Jul 10 20:58:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Mario Limonciello X-Patchwork-Id: 13729694 X-Patchwork-Delegate: bhelgaas@google.com 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 4BE071990A2; Wed, 10 Jul 2024 20:58:49 +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=1720645129; cv=none; b=Ft8Y0yvIXgBRyQY32EA6/sSkXwaItAzOqEUBJGidSlP/oA1ptSQ6RNO5lmvfv0E1KFhcch0eN8S87JRxvNdatK90ETlD9wxk/A13XZzUcBhLmyeEp1qlh4UmY3z7rNsYp/Z6M2SV5SX0XlRzP4DigBRopaqRPj41jh2nqdSdkYA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720645129; c=relaxed/simple; bh=Sf//l44VgFBV264bHR4zMgdtmXA3iNg9kC65iwFdMXs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=onTe/ku+LEoN4UTSjtkBaJIpWPvQ6zH8jZGwmUJ1eAZLookQ10cqXQkxL3o6T3FzQ+47UGdqxMbqrlaBaczAxtvmxwdaVPQ5A+PxFmH7tZh/UlbHKkLHsPIMi9FbVwg4YO5toT7EU2e/oAegHQTgxCr5hCrFj1i5X5uUWqCLPpM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=i2luYN4D; 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="i2luYN4D" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0479C4AF16; Wed, 10 Jul 2024 20:58:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720645128; bh=Sf//l44VgFBV264bHR4zMgdtmXA3iNg9kC65iwFdMXs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i2luYN4DKORwTCxfJDxCgcPHVWXq8GKs8SVlKkDGBpVi0nCVjPIH2bXGHwnz4xvu3 1hWl3iYS2WHZmFspw9yyNv1FVKexko9S9JBpjCjrifkXVA8azcRzPEact5rE4GVe/L 7NepBgu/77bBmFJnUaEkjCpjgbDB8KPAaYBAaSUSLNTBkIqgjfm0qJ5QVD26Y6qouW N/5dk7gW3yrnmKhyEE/KproCWEQ2+UNGL5amcwJKzKYzjB0j6jr2wrq7vnV3p+WzbR 8Trf707SW2FtJ26mBNpPqJoY7BqOwn/Caqs+4fy3MGd3PTcIZzWTGO7ygsNqrvv92I +UtAlYfS+iUqQ== From: superm1@kernel.org To: Bjorn Helgaas , Mathias Nyman , Mika Westerberg Cc: "open list : PCI SUBSYSTEM" , open list , "open list : USB XHCI DRIVER" , Daniel Drake , Gary Li , Greg Kroah-Hartman , Mario Limonciello Subject: [PATCH v2 2/4] PCI: Verify functions currently in D3cold have entered D0 Date: Wed, 10 Jul 2024 15:58:36 -0500 Message-ID: <20240710205838.2413465-3-superm1@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240710205838.2413465-1-superm1@kernel.org> References: <20240710205838.2413465-1-superm1@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Mario Limonciello It is reported that USB4 routers and downstream devices may behave incorrectly if a dock cable is plugged in at approximately the time that the autosuspend_delay is configured. In this situation the device has attempted to enter D3cold, but didn't finish D3cold entry when the PCI core tried to transition it back to D0. Empirically measuring this situation an "aborted" D3cold exit takes ~60ms and a "normal" D3cold exit takes ~10ms. The PCI-PM 1.2 spec specifies that the restore time for functions in D3cold is either 'Full context restore or boot latency'. As PCIe r6.0 sec 5.8 specifies that the device will have gone through a conventional reset it may take some time for the device to be ready. Wait up to 1 sec as specified in PCIe r6.0 sec 6.6.1 for a device in D3cold to return to D0. Signed-off-by: Mario Limonciello Reviewed-by: Ilpo Järvinen --- drivers/pci/pci.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 4ad02ad640518..9af324ab6bb02 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1388,6 +1388,17 @@ int pci_power_up(struct pci_dev *dev) else if (state == PCI_D2) udelay(PCI_PM_D2_DELAY); + /* + * D3cold -> D0 will have gone through a conventional reset and may need + * time to be ready. + */ + if (dev->current_state == PCI_D3cold) { + int ret; + + ret = pci_dev_wait(dev, "D3cold->D0", PCI_RESET_WAIT); + if (ret) + return ret; + } end: dev->current_state = PCI_D0; if (need_restore)