Hi, On Fri, Jul 18, 2008 at 02:10:08PM +0200, Sebastian Siewior wrote: > Commit 35b5f6b1a aka [PHYLIB: Locking fixes for PHY I/O potentially sleeping] > changed the phydev->lock from spinlock into a mutex. Now, the following > code path got triggered while NFS was unavailable: [...] > I found out that the same code path may be trigger in > - drivers/net/ucc_geth.c > - drivers/net/fec_mpc52xx.c
Recently, I described a (I think) similar problem: (http://ozlabs.org/pipermail/linuxppc-dev/2008-July/059686.html) === Hello, today, I was debugging a kernel crash on a board with a MPC5200B using 2.6.26-rc9. I found the following code in drivers/net/fec_mpc52xx.c: static irqreturn_t mpc52xx_fec_interrupt(int irq, void *dev_id) { [...] /* on fifo error, soft-reset fec */ if (ievent & (FEC_IEVENT_RFIFO_ERROR | FEC_IEVENT_XFIFO_ERROR)) { if (net_ratelimit() && (ievent & FEC_IEVENT_RFIFO_ERROR)) dev_warn(&dev->dev, "FEC_IEVENT_RFIFO_ERROR\n"); if (net_ratelimit() && (ievent & FEC_IEVENT_XFIFO_ERROR)) dev_warn(&dev->dev, "FEC_IEVENT_XFIFO_ERROR\n"); mpc52xx_fec_reset(dev); netif_wake_queue(dev); return IRQ_HANDLED; } [...] } Calling mpc52xx_fec_reset() from interrupt context is bad, at least because a) it calls phy_write, which contains BUG_ON(in_interrupt()) b) it calls mpc52xx_fec_hw_init, which has a delay-loop to check if the reset was successful (1..50 us) I assume the proper thing to do is to set a flag in the ISR and handle the soft reset later in some other context. Having never dealt with the network core and its drivers so far, I am not sure which place would be the right one to perform the soft reset. To not make things worse, I hope people with more insight to network stuff can deliver a suitable solution to this problem. All the best, Wolfram === -- Dipl.-Ing. Wolfram Sang | http://www.pengutronix.de Pengutronix - Linux Solutions for Science and Industry
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