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 045E2145B35 for ; Mon, 29 Jul 2024 12:13:36 +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=1722255217; cv=none; b=UpTS9UK6n6p+K5sdz4dw3z5+qfqIc42mpmbrLC+jIrw1aWfp1nU5AI9vgj+fZI9kyysRDlGXe31YV2tblIiiLW+GO1XuHsl8KZv4D45NWdQhDcDz14dI+X0PmRzZJ4G0QwVy5udpG4ts+JVjk631mE6fGXXX5OBjqtvTgIOoNeY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722255217; c=relaxed/simple; bh=WbYUsJqe7QkS8+7yZ7NBb2itLE2zrLSvG1TU+qRrZ2g=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=IIus7s8prATSGLnwiUs90iCMxj6IqJz+6R/rA4JOOkjP/ii1hRgJ4f7YfuJOBA61bX5a/GYP8VuLP8bdJV4+wITvOls0/gVupDkbrLdIwH2JUqnIwGjXo8s5k3JDcxHbswA8cZMfGaTugl+Sf7bnux62c4futUZO4lUpcqddJ+M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=p6DUgxu6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="p6DUgxu6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E77DC32786; Mon, 29 Jul 2024 12:13:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1722255216; bh=WbYUsJqe7QkS8+7yZ7NBb2itLE2zrLSvG1TU+qRrZ2g=; h=Subject:To:Cc:From:Date:From; b=p6DUgxu61P/uQV8giiQr45hPJ5zHexG2x9yxk0oGpa1BYh4awiQ9qfk4o7wV19yIv /wv6ISP0GhaXJlTS1osHoN8SOxYTOi785gMXUeK3FW8mF2oP1BvOtTnx0eOuymuI2t +h4ewGs/IMzI3DfcHRzK4Lyq5Iorw3aK7bYyjL6I= Subject: FAILED: patch "[PATCH] PCI: rockchip: Use GPIOD_OUT_LOW flag while requesting" failed to apply to 4.19-stable tree To: manivannan.sadhasivam@linaro.org,bhelgaas@google.com,cassel@kernel.org,kwilczynski@kernel.org,slark_xiao@163.com Cc: From: Date: Mon, 29 Jul 2024 14:13:25 +0200 Message-ID: <2024072924-yonder-factoid-6692@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x 840b7a5edf88fe678c60dee88a135647c0ea4375 # git commit -s git send-email --to '' --in-reply-to '2024072924-yonder-factoid-6692@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: 840b7a5edf88 ("PCI: rockchip: Use GPIOD_OUT_LOW flag while requesting ep_gpio") 58adbfb3ebec ("PCI: rockchip: Make 'ep-gpios' DT property optional") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 840b7a5edf88fe678c60dee88a135647c0ea4375 Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Tue, 16 Apr 2024 11:12:35 +0530 Subject: [PATCH] PCI: rockchip: Use GPIOD_OUT_LOW flag while requesting ep_gpio MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Rockchip platforms use 'GPIO_ACTIVE_HIGH' flag in the devicetree definition for ep_gpio. This means, whatever the logical value set by the driver for the ep_gpio, physical line will output the same logic level. For instance, gpiod_set_value_cansleep(rockchip->ep_gpio, 0); --> Level low gpiod_set_value_cansleep(rockchip->ep_gpio, 1); --> Level high But while requesting the ep_gpio, GPIOD_OUT_HIGH flag is currently used. Now, this also causes the physical line to output 'high' creating trouble for endpoint devices during host reboot. When host reboot happens, the ep_gpio will initially output 'low' due to the GPIO getting reset to its POR value. Then during host controller probe, it will output 'high' due to GPIOD_OUT_HIGH flag. Then during rockchip_pcie_host_init_port(), it will first output 'low' and then 'high' indicating the completion of controller initialization. On the endpoint side, each output 'low' of ep_gpio is accounted for PERST# assert and 'high' for PERST# deassert. With the above mentioned flow during host reboot, endpoint will witness below state changes for PERST#: (1) PERST# assert - GPIO POR state (2) PERST# deassert - GPIOD_OUT_HIGH while requesting GPIO (3) PERST# assert - rockchip_pcie_host_init_port() (4) PERST# deassert - rockchip_pcie_host_init_port() Now the time interval between (2) and (3) is very short as both happen during the driver probe(), and this results in a race in the endpoint. Because, before completing the PERST# deassertion in (2), endpoint got another PERST# assert in (3). A proper way to fix this issue is to change the GPIOD_OUT_HIGH flag in (2) to GPIOD_OUT_LOW. Because the usual convention is to request the GPIO with a state corresponding to its 'initial/default' value and let the driver change the state of the GPIO when required. As per that, the ep_gpio should be requested with GPIOD_OUT_LOW as it corresponds to the POR value of '0' (PERST# assert in the endpoint). Then the driver can change the state of the ep_gpio later in rockchip_pcie_host_init_port() as per the initialization sequence. This fixes the firmware crash issue in Qcom based modems connected to Rockpro64 based board. Fixes: e77f847df54c ("PCI: rockchip: Add Rockchip PCIe controller support") Closes: https://lore.kernel.org/mhi/20240402045647.GG2933@thinkpad/ Link: https://lore.kernel.org/linux-pci/20240416-pci-rockchip-perst-fix-v1-1-4800b1d4d954@linaro.org Reported-by: Slark Xiao Signed-off-by: Manivannan Sadhasivam Signed-off-by: Krzysztof Wilczyński Signed-off-by: Bjorn Helgaas Reviewed-by: Niklas Cassel Cc: stable@vger.kernel.org # v4.9 diff --git a/drivers/pci/controller/pcie-rockchip.c b/drivers/pci/controller/pcie-rockchip.c index 0ef2e622d36e..c07d7129f1c7 100644 --- a/drivers/pci/controller/pcie-rockchip.c +++ b/drivers/pci/controller/pcie-rockchip.c @@ -121,7 +121,7 @@ int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip) if (rockchip->is_rc) { rockchip->ep_gpio = devm_gpiod_get_optional(dev, "ep", - GPIOD_OUT_HIGH); + GPIOD_OUT_LOW); if (IS_ERR(rockchip->ep_gpio)) return dev_err_probe(dev, PTR_ERR(rockchip->ep_gpio), "failed to get ep GPIO\n");