[PATCH resend] Fix a lock problem in generic phy code
From: Hans-Jürgen Koch
Date: Sun Sep 09 2007 - 17:36:45 EST
I already sent this patch on August, 31. I never got an answer, so here it
is again.
Lock debugging finds a problem in phy.c and phy_device.c:
[ 3.420000] =================================
[ 3.420000] [ INFO: inconsistent lock state ]
[ 3.420000] 2.6.23-rc3-mm1 #21
[ 3.420000] ---------------------------------
[ 3.420000] inconsistent {softirq-on-W} -> {in-softirq-W} usage.
[ 3.420000] swapper/1 [HC0[0]:SC1[1]:HE1:SE0] takes:
[ 3.420000] (&dev->lock){-+..}, at: [<c017da1c>] phy_timer+0x1c/0x4c8
[ 3.420000] {softirq-on-W} state was registered at:
[ 3.420000] [<c006021c>] lock_acquire+0x94/0xac
[ 3.420000] [<c026423c>] _spin_lock+0x40/0x50
[ 3.420000] [<c017e2b4>] phy_probe+0x40/0x88
[ 3.420000] [<c017e60c>] phy_attach+0xc8/0xfc
[ 3.420000] [<c017e6c4>] phy_connect+0x1c/0x58
[ 3.420000] [<c017fc44>] macb_probe+0x4fc/0x5bc
[ 3.420000] [<c0177b44>] platform_drv_probe+0x20/0x24
[ 3.420000] [<c0176210>] driver_probe_device+0xb0/0x1bc
[ 3.420000] [<c01764dc>] __driver_attach+0xe4/0xe8
[ 3.420000] [<c017550c>] bus_for_each_dev+0x54/0x80
[ 3.420000] [<c0176074>] driver_attach+0x20/0x28
[ 3.420000] [<c01758d4>] bus_add_driver+0x84/0x1e0
[ 3.420000] [<c0176708>] driver_register+0x54/0x90
[ 3.420000] [<c0177de0>] platform_driver_register+0x6c/0x88
[ 3.420000] [<c00167ec>] macb_init+0x14/0x1c
[ 3.420000] [<c00087e4>] kernel_init+0x9c/0x2b4
[ 3.420000] [<c0040338>] do_exit+0x0/0x8e8
[ 3.420000] irq event stamp: 115025
[ 3.420000] hardirqs last enabled at (115025): [<c0264958>] _spin_unlock_irq+0x30/0x60
[ 3.420000] hardirqs last disabled at (115024): [<c02642c8>] _spin_lock_irq+0x28/0x60
[ 3.420000] softirqs last enabled at (114999): [<c0042910>] __do_softirq+0xfc/0x12c
[ 3.420000] softirqs last disabled at (115022): [<c0042ee8>] irq_exit+0x68/0x7c
[ 3.420000]
[ 3.420000] other info that might help us debug this:
[ 3.420000] no locks held by swapper/1.
[ 3.420000]
[ 3.420000] stack backtrace:
[ 3.420000] [<c0028af4>] (dump_stack+0x0/0x14) from [<c005d8e4>] (print_usage_bug+0x120/0x150)
[ 3.420000] [<c005d7c4>] (print_usage_bug+0x0/0x150) from [<c005e5e8>] (mark_lock+0x574/0x6bc)
[ 3.420000] [<c005e074>] (mark_lock+0x0/0x6bc) from [<c005f4c0>] (__lock_acquire+0x4d0/0x1198)
[ 3.420000] [<c005eff0>] (__lock_acquire+0x0/0x1198) from [<c006021c>] (lock_acquire+0x94/0xac)
[ 3.420000] [<c0060188>] (lock_acquire+0x0/0xac) from [<c026423c>] (_spin_lock+0x40/0x50)
[ 3.420000] [<c02641fc>] (_spin_lock+0x0/0x50) from [<c017da1c>] (phy_timer+0x1c/0x4c8)
[ 3.420000] r5:c098a800 r4:00000104
[ 3.420000] [<c017da00>] (phy_timer+0x0/0x4c8) from [<c0046ee4>] (run_timer_softirq+0x1a0/0x218)
[ 3.420000] r7:c081ddd0 r6:c0331e80 r5:c098aa50 r4:00000104
[ 3.420000] [<c0046d44>] (run_timer_softirq+0x0/0x218) from [<c00428a8>] (__do_softirq+0x94/0x12c)
[ 3.420000] [<c0042814>] (__do_softirq+0x0/0x12c) from [<c0042ee8>] (irq_exit+0x68/0x7c)
[ 3.420000] [<c0042e80>] (irq_exit+0x0/0x7c) from [<c0023060>] (__exception_text_start+0x60/0x74)
[ 3.420000] r4:00000001
[ 3.420000] [<c0023000>] (__exception_text_start+0x0/0x74) from [<c0023b28>] (__irq_svc+0x48/0x74)
[ 3.420000] Exception stack(0xc081de70 to 0xc081deb8)
[ 3.420000] de60: c030b2a8 c081a800 60000013 c081c000
[ 3.420000] de80: c032db40 c081dee0 c032d758 c081dece 00000012 c030b398 00000034 c081df2c
[ 3.420000] dea0: c081deb8 c081deb8 c003d6f0 c003d6f8 60000013 ffffffff
[ 3.420000] r7:00000003 r6:00000001 r5:fefff000 r4:ffffffff
[ 3.420000] [<c003d494>] (vprintk+0x0/0x474) from [<c003d930>] (printk+0x28/0x30)
[ 3.420000] [<c003d908>] (printk+0x0/0x30) from [<c01d3558>] (sock_register+0x64/0x84)
[ 3.420000] r3:00000001 r2:00000002 r1:00000001 r0:c02e4c88
[ 3.420000] [<c01d34f4>] (sock_register+0x0/0x84) from [<c001b7bc>] (af_unix_init+0x40/0x88)
[ 3.420000] r5:00000000 r4:00000000
[ 3.420000] [<c001b77c>] (af_unix_init+0x0/0x88) from [<c00087e4>] (kernel_init+0x9c/0x2b4)
[ 3.420000] r4:00000000
[ 3.420000] [<c0008748>] (kernel_init+0x0/0x2b4) from [<c0040338>] (do_exit+0x0/0x8e8)
The following patch fixes it. Tested on an AT91SAM9263-EK board, kernel 2.6.23-rc4 and -rc3-mm1.
Signed-off-by: Hans J. Koch <hjk@xxxxxxxxxxxxx>
---
Index: linux-2.6.23-rc/drivers/net/phy/phy_device.c
===================================================================
--- linux-2.6.23-rc.orig/drivers/net/phy/phy_device.c 2007-08-31 14:07:47.000000000 +0200
+++ linux-2.6.23-rc/drivers/net/phy/phy_device.c 2007-08-31 14:08:22.000000000 +0200
@@ -644,7 +644,7 @@
if (!(phydrv->flags & PHY_HAS_INTERRUPT))
phydev->irq = PHY_POLL;
- spin_lock(&phydev->lock);
+ spin_lock_bh(&phydev->lock);
/* Start out supporting everything. Eventually,
* a controller will attach, and may modify one
@@ -658,7 +658,7 @@
if (phydev->drv->probe)
err = phydev->drv->probe(phydev);
- spin_unlock(&phydev->lock);
+ spin_unlock_bh(&phydev->lock);
return err;
Index: linux-2.6.23-rc/drivers/net/phy/phy.c
===================================================================
--- linux-2.6.23-rc.orig/drivers/net/phy/phy.c 2007-08-31 14:15:20.000000000 +0200
+++ linux-2.6.23-rc/drivers/net/phy/phy.c 2007-08-31 14:15:43.000000000 +0200
@@ -755,7 +755,7 @@
*/
void phy_start(struct phy_device *phydev)
{
- spin_lock(&phydev->lock);
+ spin_lock_bh(&phydev->lock);
switch (phydev->state) {
case PHY_STARTING:
@@ -769,7 +769,7 @@
default:
break;
}
- spin_unlock(&phydev->lock);
+ spin_unlock_bh(&phydev->lock);
}
EXPORT_SYMBOL(phy_stop);
EXPORT_SYMBOL(phy_start);
-
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