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 D8B334EF143; Thu, 17 Sep 2026 16:52:13 +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=1789663935; cv=none; b=EQdokfVEDn+rTkRIPmUXlsihSyiYCDEjKUKOSY3YxDS9yu6ny3IrwIcwxVSy1WS6TKGKBpHiV517UG+P4MA6OHWqBzDcPZTxKDyXiNi8eXsXTYdC/0wIo5Tc28NJjL6qHV+c270B/6PH+wyY7lPM5oNQY8MjnBl8YZPNzaNw2R8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789663935; c=relaxed/simple; bh=qpomd2w+Klg0rZdjdUQwH0tDMbAEYF0iRb+KAiqtPwM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ijvG8AutBqM80O+dBZPRNA3y9WUGhTR/4RDjuVOjTZJbhG3t59BC+e1GxoVjGv33q+P+K4x1nd9CZGeqpO/WEJVSkquIBgU6fKxK/qNHIiUCCDJMvG26pknQHDPxljarL/NpfeYYDVY3Vtsv0VuBJIs29je3yFBz7b02sI09Bgg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=kz1HLwnP; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="kz1HLwnP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 291C91F000FF; Thu, 17 Sep 2026 16:52:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789663933; bh=VRanbwJB6pMY1NSTzccPqkkt7DanlncY37azUTp6gQo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=kz1HLwnPU/kJBJ6WyYqregCkPPirzViwAQtBWjp7pCM9A1GHmgJTW8BOH0Hz7J7MN 2wPnqAU6fDDENf8/Pbg0g2dzHlDJZRT5PqL4oUeLVF2zI3pWM5EKoj8nFZnHRx8bXg yK7hfRlAxXtQX3QGfK8TCQq7YwhjwxNW/IErqpls= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dian-Syuan Yang , Ping-Ke Shih , Sasha Levin Subject: [PATCH 6.18 0202/1250] wifi: rtw89: pci: enable LTR based on pcie control register Date: Thu, 17 Sep 2026 15:59:57 +0100 Message-ID: <20260917151557.595021953@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260917151551.901433442@linuxfoundation.org> References: <20260917151551.901433442@linuxfoundation.org> User-Agent: quilt/0.69 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-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dian-Syuan Yang [ Upstream commit 779bbe1902f29d0ef131249ddd42a8dfbe21d0fb ] Originally, driver always transmits LTR (Latency Tolerance Reporting) to pcie host, but it may cause pcie link down on some platforms because LTR is not supported. As a result, driver will check the control register of LTR setting to decide whether to enable LTR feature. This applies to Wi-Fi 6 chips only. For Wi-Fi 7 chips, although the driver still issues LTR, the hardware has its own internal logic to determine whether to actually transmit it to pcie host. Signed-off-by: Dian-Syuan Yang Signed-off-by: Ping-Ke Shih Link: https://patch.msgid.link/20260515014433.16168-5-pkshih@realtek.com Signed-off-by: Sasha Levin --- drivers/net/wireless/realtek/rtw89/pci.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/realtek/rtw89/pci.c b/drivers/net/wireless/realtek/rtw89/pci.c index b24237c1e7df7..364278a71e87d 100644 --- a/drivers/net/wireless/realtek/rtw89/pci.c +++ b/drivers/net/wireless/realtek/rtw89/pci.c @@ -3036,6 +3036,17 @@ static int rtw89_pci_mode_op(struct rtw89_dev *rtwdev) return 0; } +static bool rtw89_pci_dev_ltr_enabled(struct rtw89_dev *rtwdev) +{ + struct rtw89_pci *rtwpci = (struct rtw89_pci *)rtwdev->priv; + struct pci_dev *pdev = rtwpci->pdev; + u16 cap; + + pcie_capability_read_word(pdev, PCI_EXP_DEVCTL2, &cap); + + return !!(cap & PCI_EXP_DEVCTL2_LTR_EN); +} + static int rtw89_pci_ops_deinit(struct rtw89_dev *rtwdev) { const struct rtw89_pci_info *info = rtwdev->pci_info; @@ -3140,7 +3151,7 @@ int rtw89_pci_ltr_set(struct rtw89_dev *rtwdev, bool en) { u32 val; - if (!en) + if (!en || !rtw89_pci_dev_ltr_enabled(rtwdev)) return 0; val = rtw89_read32(rtwdev, R_AX_LTR_CTRL_0); @@ -3176,6 +3187,9 @@ int rtw89_pci_ltr_set_v1(struct rtw89_dev *rtwdev, bool en) u32 dec_ctrl; u32 val32; + if (!rtw89_pci_dev_ltr_enabled(rtwdev)) + return 0; + val32 = rtw89_read32(rtwdev, R_AX_LTR_CTRL_0); if (rtw89_pci_ltr_is_err_reg_val(val32)) return -EINVAL; -- 2.53.0