Re: [PATCH net-next v2 3/7] net: ethernet: fs_enet: drop the .adjust_link custom fs_ops
From: Andrew Lunn <andrew@lunn.ch>
Date: 2024-09-04 12:37:09
Also in:
lkml, netdev
From: Andrew Lunn <andrew@lunn.ch>
Date: 2024-09-04 12:37:09
Also in:
lkml, netdev
On Wed, Sep 04, 2024 at 10:27:11AM +0200, Maxime Chevallier wrote:
Hi Andrew, On Fri, 30 Aug 2024 23:06:08 +0200 Andrew Lunn [off-list ref] wrote:quoted
quoted
--- a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c +++ b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c@@ -649,12 +649,7 @@ static void fs_adjust_link(struct net_device *dev) unsigned long flags; spin_lock_irqsave(&fep->lock, flags); - - if (fep->ops->adjust_link) - fep->ops->adjust_link(dev); - else - generic_adjust_link(dev); - + generic_adjust_link(dev); spin_unlock_irqrestore(&fep->lock, flags);Holding a spinlock is pretty unusual. We are in thread context, and the phydev mutex is held. Looking at generic_adjust_link, do any of the fep->foo variables actually need protecting, particularly from changes in interrupts context?Yes there are, the interrupt mask/event registers are being accessed from the interrupt handler and the ->restart() hook. I can try to rework this a bit for a cleaner interrupt handling, but I don't have means to test this on all mac flavors (fec/fcc/scc) :(
As far as i can see, none of the fep->old* members are accessed outside of fs_enet-main.c. There values are not important for the restart call. So the spinlock has nothing to do with adjust_link as such, but restart. So maybe narrow down the lock to just the restart call? But it is not a big issues, just unusual. Andrew