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 A332A1E86F; Tue, 30 Jul 2024 17:04:18 +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=1722359058; cv=none; b=MPb9rFbpkWzKLjtjIyN78fvu3v3S6SD7LrV92B5z1wFxjJECSMvmhfIf2nV4Z1B4+LaW0PYuuKjOaSGDSam+QIH9RUUm0aK7GMTpoP65pdoDEecN/Kd29aoPmzTJdXKlS0vI1vsGMSJfWn5JSvo7hQjVDs6GkZn7HBp4eoEcR90= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722359058; c=relaxed/simple; bh=R9UXSmniCtQymdHvDYVM19xUXafS/54kFFg+1VFFDHM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=SwYuabvjsCmpRdXo5I6lWaKSudKbY/BzEjFgmoB6GK4FcwsOl/tgGdDnnxNgBXOvqpvhJI0khri0YcZLsPubmiwSe/8ZCC3rISO2CFGOiUq1ZNm5CECoK4JqD9N48hxsbKbd0PkzeKlg8HuzQy0q6NaD2pux/a1QjpYNOItiswM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UtKPFb9P; 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="UtKPFb9P" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28398C32782; Tue, 30 Jul 2024 17:04:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1722359058; bh=R9UXSmniCtQymdHvDYVM19xUXafS/54kFFg+1VFFDHM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UtKPFb9PxlJAYpQwKf6WM3j5hAVq8ls1F5lnZZp5vkac7jQ1MmgYenS+VTFX+N8du UMrjurePLW5k77gbxsvGnTzoT39yhyR64TLrORREDmxtPTLB/yxyOYGeFrFF23hx+V 8dWCreMnloubnzFD2Xhhm/bBEDNGKXohy1Aq82To= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Heiko Stuebner , Jianfeng Liu , Niklas Cassel , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= , Bjorn Helgaas , Manivannan Sadhasivam Subject: [PATCH 6.6 426/568] PCI: dw-rockchip: Fix initial PERST# GPIO value Date: Tue, 30 Jul 2024 17:48:53 +0200 Message-ID: <20240730151656.517678550@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240730151639.792277039@linuxfoundation.org> References: <20240730151639.792277039@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Niklas Cassel commit 28b8d7793b8573563b3d45321376f36168d77b1e upstream. PERST# is active low according to the PCIe specification. However, the existing pcie-dw-rockchip.c driver does: gpiod_set_value(..., 0); msleep(100); gpiod_set_value(..., 1); when asserting + deasserting PERST#. This is of course wrong, but because all the device trees for this compatible string have also incorrectly marked this GPIO as ACTIVE_HIGH: $ git grep -B 10 reset-gpios arch/arm64/boot/dts/rockchip/rk3568* $ git grep -B 10 reset-gpios arch/arm64/boot/dts/rockchip/rk3588* The actual toggling of PERST# is correct, and we cannot change it anyway, since that would break device tree compatibility. However, this driver does request the GPIO to be initialized as GPIOD_OUT_HIGH, which does cause a silly sequence where PERST# gets toggled back and forth for no good reason. Fix this by requesting the GPIO to be initialized as GPIOD_OUT_LOW (which for this driver means PERST# asserted). This will avoid an unnecessary signal change where PERST# gets deasserted (by devm_gpiod_get_optional()) and then gets asserted (by rockchip_pcie_start_link()) just a few instructions later. Before patch, debug prints on EP side, when booting RC: [ 845.606810] pci: PERST# asserted by host! [ 852.483985] pci: PERST# de-asserted by host! [ 852.503041] pci: PERST# asserted by host! [ 852.610318] pci: PERST# de-asserted by host! After patch, debug prints on EP side, when booting RC: [ 125.107921] pci: PERST# asserted by host! [ 132.111429] pci: PERST# de-asserted by host! This extra, very short, PERST# assertion + deassertion has been reported to cause issues with certain WLAN controllers, e.g. RTL8822CE. Fixes: 0e898eb8df4e ("PCI: rockchip-dwc: Add Rockchip RK356X host controller driver") Link: https://lore.kernel.org/linux-pci/20240417164227.398901-1-cassel@kernel.org Tested-by: Heiko Stuebner Tested-by: Jianfeng Liu Signed-off-by: Niklas Cassel Signed-off-by: Krzysztof Wilczyński Signed-off-by: Bjorn Helgaas Reviewed-by: Heiko Stuebner Reviewed-by: Manivannan Sadhasivam Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Greg Kroah-Hartman --- drivers/pci/controller/dwc/pcie-dw-rockchip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c +++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c @@ -240,7 +240,7 @@ static int rockchip_pcie_resource_get(st return PTR_ERR(rockchip->apb_base); rockchip->rst_gpio = devm_gpiod_get_optional(&pdev->dev, "reset", - GPIOD_OUT_HIGH); + GPIOD_OUT_LOW); if (IS_ERR(rockchip->rst_gpio)) return PTR_ERR(rockchip->rst_gpio);