| Message ID | 20220526013714.4119839-1-tee.min.tan@linux.intel.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,1/1] net: phy: dp83867: retrigger SGMII AN when link change | expand |
On Thu, 26 May 2022 09:37:14 +0800 Tan Tee Min wrote: > There is a limitation in TI DP83867 PHY device where SGMII AN is only > triggered once after the device is booted up. Even after the PHY TPI is > down and up again, SGMII AN is not triggered and hence no new in-band > message from PHY to MAC side SGMII. > > This could cause an issue during power up, when PHY is up prior to MAC. > At this condition, once MAC side SGMII is up, MAC side SGMII wouldn`t > receive new in-band message from TI PHY with correct link status, speed > and duplex info. > > As suggested by TI, implemented a SW solution here to retrigger SGMII > Auto-Neg whenever there is a link change. Thanks, sounds like this bug has always been in the driver so we should add: Fixes: 2a10154abcb7 ("net: phy: dp83867: Add TI dp83867 phy") Is that right? Getting a workaround like this into stable eventually seems like a good idea so Fixes tag will help.
On Wed, May 25, 2022 at 09:56:29PM -0700, Jakub Kicinski wrote: > On Thu, 26 May 2022 09:37:14 +0800 Tan Tee Min wrote: > > As suggested by TI, implemented a SW solution here to retrigger SGMII > > Auto-Neg whenever there is a link change. > > Thanks, sounds like this bug has always been in the driver so we should > add: > > Fixes: 2a10154abcb7 ("net: phy: dp83867: Add TI dp83867 phy") > > Is that right? Getting a workaround like this into stable eventually > seems like a good idea so Fixes tag will help. Thanks for the quick response. Yes, you are right. Let me add the Fixes tag and Cc <stable@vger.kernel.org> in v2 patch. Thanks, Tee Min
diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c index 8561f2d4443b..13dafe7a29bd 100644 --- a/drivers/net/phy/dp83867.c +++ b/drivers/net/phy/dp83867.c @@ -137,6 +137,7 @@ #define DP83867_DOWNSHIFT_2_COUNT 2 #define DP83867_DOWNSHIFT_4_COUNT 4 #define DP83867_DOWNSHIFT_8_COUNT 8 +#define DP83867_SGMII_AUTONEG_EN BIT(7) /* CFG3 bits */ #define DP83867_CFG3_INT_OE BIT(7) @@ -855,6 +856,32 @@ static int dp83867_phy_reset(struct phy_device *phydev) DP83867_PHYCR_FORCE_LINK_GOOD, 0); } +static void dp83867_link_change_notify(struct phy_device *phydev) +{ + /* There is a limitation in DP83867 PHY device where SGMII AN is + * only triggered once after the device is booted up. Even after the + * PHY TPI is down and up again, SGMII AN is not triggered and + * hence no new in-band message from PHY to MAC side SGMII. + * This could cause an issue during power up, when PHY is up prior + * to MAC. At this condition, once MAC side SGMII is up, MAC side + * SGMII wouldn`t receive new in-band message from TI PHY with + * correct link status, speed and duplex info. + * Thus, implemented a SW solution here to retrigger SGMII Auto-Neg + * whenever there is a link change. + */ + if (phydev->interface == PHY_INTERFACE_MODE_SGMII) { + int val = 0; + + val = phy_clear_bits(phydev, DP83867_CFG2, + DP83867_SGMII_AUTONEG_EN); + if (val < 0) + return; + + phy_set_bits(phydev, DP83867_CFG2, + DP83867_SGMII_AUTONEG_EN); + } +} + static struct phy_driver dp83867_driver[] = { { .phy_id = DP83867_PHY_ID, @@ -879,6 +906,8 @@ static struct phy_driver dp83867_driver[] = { .suspend = genphy_suspend, .resume = genphy_resume, + + .link_change_notify = dp83867_link_change_notify, }, }; module_phy_driver(dp83867_driver);