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 C91902AF07; Mon, 28 Oct 2024 06:49:08 +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=1730098148; cv=none; b=UpU2/oZq/AJkMLiSc/6HlXCA5hCY6minaewVnFrsqAPK91r4MJ8egNaxYikTkIwEUhtC/Ht72bgqDhKVkcvzVym8YMfvjVQsQvANxAleiTv0DqStB4MsYKM3F+IYeqPnF2y0ytW9f0p8LFBwl/iU40WSfwQEOtatXqIG6m46bIk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730098148; c=relaxed/simple; bh=qdv3MrGmrzToV/C9onyWWxQQeZjTOl8abDpeGuOggT8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XrEbF5/qblUa9B+Dp1vk0qpZIUlYzbuQZ3I2dMaqJcHxhDEAEJ6QjRCl+hfAHXbIXuyV4mafTqlQoy+Qu72DIBWFPfPagc+zW0RNfvUvoNFb6a/voTND/Dk35qBVfCPrHVIHDV9sNey0SJML6N48Z117trC7kwwzw3Q5QM+Mrhs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LKYjyIG3; 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="LKYjyIG3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 671AEC4CEC3; Mon, 28 Oct 2024 06:49:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730098148; bh=qdv3MrGmrzToV/C9onyWWxQQeZjTOl8abDpeGuOggT8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LKYjyIG3+tWsxHpuP69qulotB3Beq6MEQby8npHzWs5Awl4PGsSX+067D8jp8cctF FDynhlh2D6rMN0y+auaEfDHqi2ye9ve2KydZqt+QdhNqkIg2EEPybYTFT1CRgqMkrG 9s+0cFEa5CtvuiSPiK9G3BQX77J3IURWa9Xvnqsk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paritosh Dixit , Paolo Abeni , Sasha Levin Subject: [PATCH 6.11 061/261] net: stmmac: dwmac-tegra: Fix link bring-up sequence Date: Mon, 28 Oct 2024 07:23:23 +0100 Message-ID: <20241028062313.558202569@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241028062312.001273460@linuxfoundation.org> References: <20241028062312.001273460@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paritosh Dixit [ Upstream commit 1cff6ff302f5703a627f9ee1d99131161ea2683e ] The Tegra MGBE driver sometimes fails to initialize, reporting the following error, and as a result, it is unable to acquire an IP address with DHCP: tegra-mgbe 6800000.ethernet: timeout waiting for link to become ready As per the recommendation from the Tegra hardware design team, fix this issue by: - clearing the PHY_RDY bit before setting the CDR_RESET bit and then setting PHY_RDY bit before clearing CDR_RESET bit. This ensures valid data is present at UPHY RX inputs before starting the CDR lock. - adding the required delays when bringing up the UPHY lane. Note we need to use delays here because there is no alternative, such as polling, for these cases. Using the usleep_range() instead of ndelay() as sleeping is preferred over busy wait loop. Without this change we would see link failures on boot sometimes as often as 1 in 5 boots. With this fix we have not observed any failures in over 1000 boots. Fixes: d8ca113724e7 ("net: stmmac: tegra: Add MGBE support") Signed-off-by: Paritosh Dixit Link: https://patch.msgid.link/20241010142908.602712-1-paritoshd@nvidia.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/ethernet/stmicro/stmmac/dwmac-tegra.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-tegra.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-tegra.c index 362f85136c3ef..6fdd94c8919ec 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-tegra.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-tegra.c @@ -127,10 +127,12 @@ static int mgbe_uphy_lane_bringup_serdes_up(struct net_device *ndev, void *mgbe_ value &= ~XPCS_WRAP_UPHY_RX_CONTROL_AUX_RX_IDDQ; writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); + usleep_range(10, 20); /* 50ns min delay needed as per HW design */ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); value &= ~XPCS_WRAP_UPHY_RX_CONTROL_RX_SLEEP; writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); + usleep_range(10, 20); /* 500ns min delay needed as per HW design */ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_CAL_EN; writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); @@ -143,22 +145,30 @@ static int mgbe_uphy_lane_bringup_serdes_up(struct net_device *ndev, void *mgbe_ return err; } + usleep_range(10, 20); /* 50ns min delay needed as per HW design */ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_DATA_EN; writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); - value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_CDR_RESET; + value &= ~XPCS_WRAP_UPHY_RX_CONTROL_RX_PCS_PHY_RDY; writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); + usleep_range(10, 20); /* 50ns min delay needed as per HW design */ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); - value &= ~XPCS_WRAP_UPHY_RX_CONTROL_RX_CDR_RESET; + value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_CDR_RESET; writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); + usleep_range(10, 20); /* 50ns min delay needed as per HW design */ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_PCS_PHY_RDY; writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); + msleep(30); /* 30ms delay needed as per HW design */ + value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); + value &= ~XPCS_WRAP_UPHY_RX_CONTROL_RX_CDR_RESET; + writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL); + err = readl_poll_timeout(mgbe->xpcs + XPCS_WRAP_IRQ_STATUS, value, value & XPCS_WRAP_IRQ_STATUS_PCS_LINK_STS, 500, 500 * 2000); -- 2.43.0