New: IRQ problem using PLIP installing linux on OLD IBM laptop

Bugme-new Andrew Morton 2 participants 2 messages Apr 10, 2008 1 message not in the archive

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Andrew Morton

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2008-04-10 16:47 UTC #1 lore raw

(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface).

Quoted 44 lines · On Thu, 10 Apr 2008 02:27:07 -0700 (PDT) [email protected] wrote:

http://bugzilla.kernel.org/show_bug.cgi?id=10435

           Summary: IRQ problem using PLIP installing linux on OLD IBM
                    laptop
           Product: Drivers
           Version: 2.5
     KernelVersion: 2.6.24.4-vanilla, 2.6.18-debian-stable
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: Parallel
        AssignedTo: [email protected]
        ReportedBy: [email protected]

Latest working kernel version:
Earliest failing kernel version:
Distribution:
Hardware Environment: PLIP, LPT
Software Environment: Debian stable, Debian testing Problem Description:

plip0: checksum error
Unbalanced enable for IRQ 7

WARNING: at kernel/irq/manage.c:174 enable_irq()

Pid: 8, comm: events/1 Not tainted 2.6.24.4 #3

Call Trace:
 [<ffffffff80264f11>] enable_irq+0x7a/0xba
 [<ffffffff8817cac8>] :plip:plip_error+0x7b/0xaf
 [<ffffffff8817c21b>] :plip:plip_bh+0x4e/0x274
 [<ffffffff8817c1cd>] :plip:plip_bh+0x0/0x274
 [<ffffffff8024227e>] run_workqueue+0x87/0x11a
 [<ffffffff80242c96>] worker_thread+0xe1/0xf0
 [<ffffffff80245de4>] autoremove_wake_function+0x0/0x2e
 [<ffffffff80242bb5>] worker_thread+0x0/0xf0
 [<ffffffff80245cc2>] kthread+0x47/0x75
 [<ffffffff8020c5e8>] child_rip+0xa/0x12
 [<ffffffff80245c7b>] kthread+0x0/0x75
 [<ffffffff8020c5de>] child_rip+0x0/0x12

Quoted 8 lines

I see little bit different stack trace also at old IBM laptop side. Will try post photo.
There are also lot of plip0: transmit timeout(1,80) messages on both sides.
Steps to reproduce:
Connect computers using parallel laplink cable, try networking

We did recently fix an interrupt-related bug in plip, but I doubt if it'll fix this problem. The patch is below. I'll forward it to the -stable team for consideration in 2.6.24.x.

I assume that the driver actually continues to work OK, and that this is just an irritating warning?

commit cabce28ec0a0ae3d0ddfa4461f0e8be94ade9e46

Author: Mikulas Patocka <[email protected]>
Date:   Tue Apr 1 01:22:45 2008 +0200

plip: replace spin_lock_irq with spin_lock_irqsave in irq context

Plip uses spin_lock_irq/spin_unlock_irq in its IRQ handler (called from parport IRQ handler), the latter enables interrupts without parport subsystem IRQ handler expecting it.

The bug can be seen if you compile kernel with lock dependency checking and use plip --- it produces a warning.

This patch changes it to spin_lock_irqsave/spin_lock_irqrestore, so that it doesn't enable interrupts when already disabled.

Signed-off-by Linus Torvalds <[email protected]>

drivers/net/plip.c +4 -3

index fee3d7b..1e96542 100644
@@ -903,17 +903,18 @@ plip_interrupt(void *dev_id)
 	struct net_local *nl;
 	struct plip_local *rcv;
 	unsigned char c0;
+	unsigned long flags;
 
 	nl = netdev_priv(dev);
 	rcv = &nl->rcv_data;
 
-	spin_lock_irq (&nl->lock);
+	spin_lock_irqsave (&nl->lock, flags);
 
 	c0 = read_status(dev);
 	if ((c0 & 0xf8) != 0xc0) {
 		if ((dev->irq != -1) && (net_debug > 1))
 			printk(KERN_DEBUG "%s: spurious interrupt\n", dev->name);
-		spin_unlock_irq (&nl->lock);
+		spin_unlock_irqrestore (&nl->lock, flags);
 		return;
 	}

@@ -942,7 +943,7 @@ plip_interrupt(void *dev_id)
 		break;
 	}
 
-	spin_unlock_irq(&nl->lock);
+	spin_unlock_irqrestore(&nl->lock, flags);
 }
 
 static int

Mikulas Patocka

2008-04-10 17:37 UTC #2 lore raw

Quoted 52 lines · Andrew Morton

(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface).
Quoted 47 lines · On Thu, 10 Apr 2008 02:27:07 -0700 (PDT) [email protected] wrote:
http://bugzilla.kernel.org/show_bug.cgi?id=10435
           Summary: IRQ problem using PLIP installing linux on OLD IBM
                    laptop
           Product: Drivers
           Version: 2.5
     KernelVersion: 2.6.24.4-vanilla, 2.6.18-debian-stable
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: Parallel
        AssignedTo: [email protected]
        ReportedBy: [email protected]
Latest working kernel version:
Earliest failing kernel version:
Distribution:
Hardware Environment: PLIP, LPT
Software Environment: Debian stable, Debian testing Problem Description:
plip0: checksum error
Unbalanced enable for IRQ 7
WARNING: at kernel/irq/manage.c:174 enable_irq()
Pid: 8, comm: events/1 Not tainted 2.6.24.4 #3
Call Trace:
 [<ffffffff80264f11>] enable_irq+0x7a/0xba
 [<ffffffff8817cac8>] :plip:plip_error+0x7b/0xaf
 [<ffffffff8817c21b>] :plip:plip_bh+0x4e/0x274
 [<ffffffff8817c1cd>] :plip:plip_bh+0x0/0x274
 [<ffffffff8024227e>] run_workqueue+0x87/0x11a
 [<ffffffff80242c96>] worker_thread+0xe1/0xf0
 [<ffffffff80245de4>] autoremove_wake_function+0x0/0x2e
 [<ffffffff80242bb5>] worker_thread+0x0/0xf0
 [<ffffffff80245cc2>] kthread+0x47/0x75
 [<ffffffff8020c5e8>] child_rip+0xa/0x12
 [<ffffffff80245c7b>] kthread+0x0/0x75
 [<ffffffff8020c5de>] child_rip+0x0/0x12
I see little bit different stack trace also at old IBM laptop side. Will try post photo. There are also lot of plip0: transmit timeout(1,80) messages on both sides.

Regarding the timeouts --- shouldn't the plip timeout message be removed? Or enabled only for debugging? The protocol is (mis)designed in such a way that timeouts are inevitable.

Mikulas