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 CF2DB1BE22A; Tue, 2 Jul 2024 17:07:46 +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=1719940066; cv=none; b=QgPTx3kUe6k+604oXflPneCTF/D+e2xcs4gL4/DlaDHtgRjwYU0zFdC1j0sbxKs4lqEH7CzejXbW4az6KBkQZOC7BXvCFpt3fIA+pdqLhi7hAt1szcA9qN8hv+jOK4MXPpm5ekgmONCpzIuI9QDAGNamWS0J97+ICJ7yW+FWsnE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719940066; c=relaxed/simple; bh=WF8IOG8ZwW7onlW0mmxyl410i4XyKJGhSfncyZlyJKw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=V9Rh3yIo3KrxuucSh/wLcXtCec87GcHls5uEm53w+bKrsCgSQORG2DA3qC52EzXcRfLjmklphOeFQl7Vr1+GmGXhtyQkqnOEOvedMBOJMOrpHkBfY+NlWum+cM8qkrp+kz7Ow6+0IPaDzKa+d0IqHCoXEtSrLt8ZKmdgZKzjuuw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=d0teGZMc; 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="d0teGZMc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C222C4AF07; Tue, 2 Jul 2024 17:07:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1719940066; bh=WF8IOG8ZwW7onlW0mmxyl410i4XyKJGhSfncyZlyJKw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d0teGZMccXZQuff9JhuTPRiWWGje6MyABr58tolzjdrPIy+ZKOKEtRci9sHkIb4Nr GvPQrIcDR6f5rB2YBh723KTbt3cETlqhpGz/aHJ3djfPhTSQ+pvZrj3bMxsobctAGl TQN65JcbJwnNA8RMmpLe7XHAzIKHSqXWAW6DZfBE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Enguerrand de Ribaucourt , Woojung Huh , Arun Ramadoss , Andrew Lunn , "David S. Miller" , Sasha Levin Subject: [PATCH 6.9 041/222] net: dsa: microchip: use collision based back pressure mode Date: Tue, 2 Jul 2024 19:01:19 +0200 Message-ID: <20240702170245.545649349@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240702170243.963426416@linuxfoundation.org> References: <20240702170243.963426416@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-Transfer-Encoding: 8bit 6.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Enguerrand de Ribaucourt [ Upstream commit d963c95bc9840d070a788c35e41b715a648717f7 ] Errata DS80000758 states that carrier sense back pressure mode can cause link down issues in 100BASE-TX half duplex mode. The datasheet also recommends to always use the collision based back pressure mode. Fixes: b987e98e50ab ("dsa: add DSA switch driver for Microchip KSZ9477") Signed-off-by: Enguerrand de Ribaucourt Reviewed-by: Woojung Huh Acked-by: Arun Ramadoss Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/dsa/microchip/ksz9477.c | 4 ++++ drivers/net/dsa/microchip/ksz9477_reg.h | 1 + 2 files changed, 5 insertions(+) diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c index 05767d3025f77..dde5c65c2c366 100644 --- a/drivers/net/dsa/microchip/ksz9477.c +++ b/drivers/net/dsa/microchip/ksz9477.c @@ -1303,6 +1303,10 @@ int ksz9477_setup(struct dsa_switch *ds) /* Enable REG_SW_MTU__2 reg by setting SW_JUMBO_PACKET */ ksz_cfg(dev, REG_SW_MAC_CTRL_1, SW_JUMBO_PACKET, true); + /* Use collision based back pressure mode. */ + ksz_cfg(dev, REG_SW_MAC_CTRL_1, SW_BACK_PRESSURE, + SW_BACK_PRESSURE_COLLISION); + /* Now we can configure default MTU value */ ret = regmap_update_bits(ksz_regmap_16(dev), REG_SW_MTU__2, REG_SW_MTU_MASK, VLAN_ETH_FRAME_LEN + ETH_FCS_LEN); diff --git a/drivers/net/dsa/microchip/ksz9477_reg.h b/drivers/net/dsa/microchip/ksz9477_reg.h index f3a205ee483f2..fb124be8edd30 100644 --- a/drivers/net/dsa/microchip/ksz9477_reg.h +++ b/drivers/net/dsa/microchip/ksz9477_reg.h @@ -247,6 +247,7 @@ #define REG_SW_MAC_CTRL_1 0x0331 #define SW_BACK_PRESSURE BIT(5) +#define SW_BACK_PRESSURE_COLLISION 0 #define FAIR_FLOW_CTRL BIT(4) #define NO_EXC_COLLISION_DROP BIT(3) #define SW_JUMBO_PACKET BIT(2) -- 2.43.0