diff options
| author | Dave Jones <davej@redhat.com> | 2006-09-25 16:51:26 -0700 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-10-01 20:03:19 +0100 |
| commit | e480af09c49736848f749a43dff2c902104f6691 (patch) | |
| tree | 7633780bd833e7770233dd931d7189100e972f49 /drivers/serial/8250.c | |
| parent | a6b93a908508810c5d51dd9b390283345af6f2d9 (diff) | |
[SERIAL] tickle NMI watchdog on serial output.
Serial is _slow_ sometimes. So slow, that the NMI watchdog kicks in.
NMI Watchdog detected LOCKUP on CPU2CPU 2
Modules linked in: loop usb_storage md5 ipv6 parport_pc lp parport autofs4 i2c_dev i2c_core rfcomm l2cap bluetooth sunrpc pcdPid: 3138, comm: gpm Not tainted 2.6.11-1.1290_FC4smp
RIP: 0010:[<ffffffff80273b8a>] <ffffffff80273b8a>{serial_in+106}
RSP: 0018:ffff81003afc3d50 EFLAGS: 00000002
RAX: 0000000000000020 RBX: 0000000000000020 RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000005 RDI: ffffffff804dcd60
RBP: 00000000000024fc R08: 000000000000000a R09: 0000000000000033
R10: ffff81001beb7c20 R11: 0000000000000020 R12: ffffffff804dcd60
R13: ffffffff804ade76 R14: 000000000000002b R15: 000000000000002c
FS: 00002aaaaaac4920(0000) GS:ffffffff804fca00(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00002aaaaabcb000 CR3: 000000003c0d0000 CR4: 00000000000006e0
Process gpm (pid: 3138, threadinfo ffff81003afc2000, task ffff81003eb63780)
Stack: ffffffff80275f2e 0000000000000000 ffffffff80448380 0000000000007d6b
000000000000002c fffffffffffffbbf 0000000000000292 0000000000008000
ffffffff80138e8c 0000000000007d97
Call Trace:<ffffffff80275f2e>{serial8250_console_write+270} <ffffffff80138e8c>{__call_console_drivers+76}
<ffffffff8013914b>{release_console_sem+315} <ffffffff80260325>{con_open+149}
<ffffffff80254e99>{tty_open+537} <ffffffff80192713>{chrdev_open+387}
<ffffffff80188824>{dentry_open+260} <ffffffff80188994>{filp_open+68}
<ffffffff80187b73>{get_unused_fd+227} <ffffffff80188a6c>{sys_open+76}
<ffffffff8010ebc6>{tracesys+209}
Code: 0f b6 c0 c3 66 90 41 57 49 89 f7 41 56 41 be 00 01 00 00 41
console shuts up ...
I initially did the patch below a year ago for the Fedora kernel, and have
been keeping it up to date since. I recently got the same thing happening
on a vanilla kernel, so figured it was time to repost this.
Signed-off-by: Dave Jones <davej@redhat.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/serial/8250.c')
| -rw-r--r-- | drivers/serial/8250.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index a07442ffefb..0ede0ee6424 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -2232,9 +2232,10 @@ static inline void wait_for_xmitr(struct uart_8250_port *up, int bits) /* Wait up to 1s for flow control if necessary */ if (up->port.flags & UPF_CONS_FLOW) { tmout = 1000000; - while (--tmout && - ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0)) + while (!(serial_in(up, UART_MSR) & UART_MSR_CTS) && --tmout) { udelay(1); + touch_nmi_watchdog(); + } } } |