Re: [PATCH] net: phy: fix auto-negotiation stall due to unavailable interrupt

From: Sergei Shtylyov
Date: Wed Apr 19 2017 - 14:11:58 EST


Hello!

On 04/19/2017 04:46 PM, Alexander Kochetkov wrote:

The problem I fix related to SMSC LAN8710/LAN8720 PHY handled using
interrupts. During power-up cycle the PHY do auto-negotiation, generate
interrupt and set BMSR_ANEGCOMPLETE flag. Interrupt is handled by PHY
state machine but doesn't update link because PHY is in PHY_READY state.
After some time MAC bring up and connect with PHY. It start PHY using
phy_start(). During startup PHY change state to PHY_AN but doesn't
set BMCR_ANRESTART flag due to genphy_config_aneg() doesn't update MII_BMCR
because there no new to advertising. As a result, state machine wait for
^^^^^^^^^^^^ ^^^^^^^^^^^
There is no new what? Advertize, maybe?

interrupt from PHY and nether get "link is up". Because BMSR_ANEGCOMPLETE
^^^^^^
Never, neither? :-)

already set the patch schedule check link without waiting interrupt.
In case genphy_config_aneg() update MII_BMCR and set BMCR_ANRESTART
flag, BMSR_ANEGCOMPLETE will be cleared and state machine will continue
on auto-negotiation interrupt.

Signed-off-by: Alexander Kochetkov <al.kochet@xxxxxxxxx>
[...]

MBR, Sergei