| Message ID | 20250114164721.2879380-1-vladimir.oltean@nxp.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 5c71729ab92c7e710d48ed93043a2d1e35cc8d3c |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,1/2] net: pcs: xpcs: fix DW_VR_MII_DIG_CTRL1_2G5_EN bit being set for 1G SGMII w/o inband | expand |
Hello Vlad, On Tue, 14 Jan 2025 18:47:20 +0200 Vladimir Oltean <vladimir.oltean@nxp.com> wrote: > On a port with SGMII fixed-link at SPEED_1000, DW_VR_MII_DIG_CTRL1 gets > set to 0x2404. This is incorrect, because bit 2 (DW_VR_MII_DIG_CTRL1_2G5_EN) > is set. > > It comes from the previous write to DW_VR_MII_AN_CTRL, because the "val" > variable is reused and is dirty. Actually, its value is 0x4, aka > FIELD_PREP(DW_VR_MII_PCS_MODE_MASK, DW_VR_MII_PCS_MODE_C37_SGMII). > > Resolve the issue by clearing "val" to 0 when writing to a new register. > After the fix, the register value is 0x2400. > > Prior to the blamed commit, when the read-modify-write was open-coded, > the code saved the content of the DW_VR_MII_DIG_CTRL1 register in the > "ret" variable. > > Fixes: ce8d6081fcf4 ("net: pcs: xpcs: add _modify() accessors") > Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Thanks, Maxime
On Tue, Jan 14, 2025 at 06:47:20PM +0200, Vladimir Oltean wrote: > On a port with SGMII fixed-link at SPEED_1000, DW_VR_MII_DIG_CTRL1 gets > set to 0x2404. This is incorrect, because bit 2 (DW_VR_MII_DIG_CTRL1_2G5_EN) > is set. > > It comes from the previous write to DW_VR_MII_AN_CTRL, because the "val" > variable is reused and is dirty. Actually, its value is 0x4, aka > FIELD_PREP(DW_VR_MII_PCS_MODE_MASK, DW_VR_MII_PCS_MODE_C37_SGMII). > > Resolve the issue by clearing "val" to 0 when writing to a new register. > After the fix, the register value is 0x2400. > > Prior to the blamed commit, when the read-modify-write was open-coded, > the code saved the content of the DW_VR_MII_DIG_CTRL1 register in the > "ret" variable. > > Fixes: ce8d6081fcf4 ("net: pcs: xpcs: add _modify() accessors") > Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Good catch! Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Thanks!
Hello: This series was applied to netdev/net.git (main) by Jakub Kicinski <kuba@kernel.org>: On Tue, 14 Jan 2025 18:47:20 +0200 you wrote: > On a port with SGMII fixed-link at SPEED_1000, DW_VR_MII_DIG_CTRL1 gets > set to 0x2404. This is incorrect, because bit 2 (DW_VR_MII_DIG_CTRL1_2G5_EN) > is set. > > It comes from the previous write to DW_VR_MII_AN_CTRL, because the "val" > variable is reused and is dirty. Actually, its value is 0x4, aka > FIELD_PREP(DW_VR_MII_PCS_MODE_MASK, DW_VR_MII_PCS_MODE_C37_SGMII). > > [...] Here is the summary with links: - [net,1/2] net: pcs: xpcs: fix DW_VR_MII_DIG_CTRL1_2G5_EN bit being set for 1G SGMII w/o inband https://git.kernel.org/netdev/net/c/5c71729ab92c - [net,2/2] net: pcs: xpcs: actively unset DW_VR_MII_DIG_CTRL1_2G5_EN for 1G SGMII https://git.kernel.org/netdev/net/c/d6e3316a1680 You are awesome, thank you!
diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c index e270a75a988c..3de0a25a1eca 100644 --- a/drivers/net/pcs/pcs-xpcs.c +++ b/drivers/net/pcs/pcs-xpcs.c @@ -728,6 +728,7 @@ static int xpcs_config_aneg_c37_sgmii(struct dw_xpcs *xpcs, if (ret < 0) return ret; + val = 0; mask = DW_VR_MII_DIG_CTRL1_MAC_AUTO_SW; if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED) val = DW_VR_MII_DIG_CTRL1_MAC_AUTO_SW;
On a port with SGMII fixed-link at SPEED_1000, DW_VR_MII_DIG_CTRL1 gets set to 0x2404. This is incorrect, because bit 2 (DW_VR_MII_DIG_CTRL1_2G5_EN) is set. It comes from the previous write to DW_VR_MII_AN_CTRL, because the "val" variable is reused and is dirty. Actually, its value is 0x4, aka FIELD_PREP(DW_VR_MII_PCS_MODE_MASK, DW_VR_MII_PCS_MODE_C37_SGMII). Resolve the issue by clearing "val" to 0 when writing to a new register. After the fix, the register value is 0x2400. Prior to the blamed commit, when the read-modify-write was open-coded, the code saved the content of the DW_VR_MII_DIG_CTRL1 register in the "ret" variable. Fixes: ce8d6081fcf4 ("net: pcs: xpcs: add _modify() accessors") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- drivers/net/pcs/pcs-xpcs.c | 1 + 1 file changed, 1 insertion(+)