This is a note to let you know that I've just added the patch titled net: ethernet: ti: cpsw: add check for in-band mode setting with RGMII PHY interface to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-ethernet-ti-cpsw-add-check-for-in-band-mode-setting-with-rgmii-phy-interface.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Mar 29 08:33:08 CEST 2018 From: "SZ Lin (林上智)" <sz.lin@xxxxxxxx> Date: Fri, 16 Mar 2018 00:56:01 +0800 Subject: net: ethernet: ti: cpsw: add check for in-band mode setting with RGMII PHY interface From: "SZ Lin (林上智)" <sz.lin@xxxxxxxx> [ Upstream commit f9db50691db4a7d860fce985f080bb3fc23a7ede ] According to AM335x TRM[1] 14.3.6.2, AM437x TRM[2] 15.3.6.2 and DRA7 TRM[3] 24.11.4.8.7.3.3, in-band mode in EXT_EN(bit18) register is only available when PHY is configured in RGMII mode with 10Mbps speed. It will cause some networking issues without RGMII mode, such as carrier sense errors and low throughput. TI also mentioned this issue in their forum[4]. This patch adds the check mechanism for PHY interface with RGMII interface type, the in-band mode can only be set in RGMII mode with 10Mbps speed. References: [1]: https://www.ti.com/lit/ug/spruh73p/spruh73p.pdf [2]: http://www.ti.com/lit/ug/spruhl7h/spruhl7h.pdf [3]: http://www.ti.com/lit/ug/spruic2b/spruic2b.pdf [4]: https://e2e.ti.com/support/arm/sitara_arm/f/791/p/640765/2392155 Suggested-by: Holsety Chen (陳憲輝) <Holsety.Chen@xxxxxxxx> Signed-off-by: SZ Lin (林上智) <sz.lin@xxxxxxxx> Signed-off-by: Schuyler Patton <spatton@xxxxxx> Reviewed-by: Grygorii Strashko <grygorii.strashko@xxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/ti/cpsw.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/net/ethernet/ti/cpsw.c +++ b/drivers/net/ethernet/ti/cpsw.c @@ -878,7 +878,8 @@ static void _cpsw_adjust_link(struct cps /* set speed_in input in case RMII mode is used in 100Mbps */ if (phy->speed == 100) mac_control |= BIT(15); - else if (phy->speed == 10) + /* in band mode only works in 10Mbps RGMII mode */ + else if ((phy->speed == 10) && phy_interface_is_rgmii(phy)) mac_control |= BIT(18); /* In Band mode */ if (priv->rx_pause) Patches currently in stable-queue which might be from sz.lin@xxxxxxxx are queue-4.4/net-ethernet-ti-cpsw-add-check-for-in-band-mode-setting-with-rgmii-phy-interface.patch