I'm actively googling this without success... so I try here, before
resorting to linux-kernel :(
I seem to remember having read something about it in the past, but no
luck finding it till now... please HELP :)
I'm plagued by a nasty problem on a SuperMicro ServerWorks dual Xeon no
HT. the system timer slows down like to a crawl. I mean the effect is
that 'date' reports a backward time. ntp seems not able to compensate.
It is related to the interaction with a custom developed PCI 66MHz 64bit
card (PLD APPLICATIONS:5555) card, driven by a very simple char device
driver.
It's simple consider the card as guilty, but it's running ok on a number
of other systems, admittedly not ServerWorks, so I'm not sure of
anything. The card can only be a stresser...
in the driver, the typical code path is:
- drv_ioctl() to read/write MMIO register
down_interruptible( &(hib[min].i2csem[i2c_index]) )
....
REGW (min, bar, off-0x200, io.cmd); /* write cmd */
....
ret = poll_i2c_not_busy ( min, bar, i2c_index );
....
up (&(hib[min].i2csem[i2c_index]));
- drv_read()/drv_write() uses DMA
driver is OpenSource so no problem ;)
kernel 2.4.22-1.2199.5.legacy.nptlsmp
processor : 1
vendor_id : GenuineIntel
cpu family : 15
model : 2
model name : Intel(R) Xeon(TM) CPU 2.66GHz
stepping : 5
cpu MHz : 2665.974
cache size : 512 KB
CPU0 CPU1
0: 1454286 1525524 IO-APIC-edge timer
1: 1802 2143 IO-APIC-edge keyboard
2: 0 0 XT-PIC cascade
5: 0 0 XT-PIC hib
8: 1 0 IO-APIC-edge rtc
10: 0 0 IO-APIC-level usb-ohci
11: 0 0 XT-PIC hib , hib , hib
14: 1173150 1236871 IO-APIC-edge ide0
15: 2 0 IO-APIC-edge ide1
16: 35 0 IO-APIC-level aic79xx
17: 35 0 IO-APIC-level aic79xx
30: 1250968 0 IO-APIC-level eth0
NMI: 12271 126463
LOC: 2979940 2979933
ERR: 0
MIS: 0
00:00.0 Host bridge: ServerWorks CNB20-HE Host Bridge (rev 31)
00:00.1 Host bridge: ServerWorks CNB20-HE Host Bridge
00:00.2 Host bridge: ServerWorks CNB20-HE Host Bridge
00:02.0 VGA compatible controller: ATI Technologies Inc Rage XL (rev 27)
00:04.0 Ethernet controller: Intel Corp. 82540EM Gigabit Ethernet
Controller (rev 02)
00:0f.0 ISA bridge: ServerWorks CSB5 South Bridge (rev 93)
00:0f.1 IDE interface: ServerWorks CSB5 IDE Controller (rev 93)
00:0f.2 USB Controller: ServerWorks OSB4/CSB5 OHCI USB Controller (rev 05)
00:0f.3 Host bridge: ServerWorks GCLE Host Bridge
00:10.0 Host bridge: ServerWorks: Unknown device 0101 (rev 03)
00:10.2 Host bridge: ServerWorks: Unknown device 0101 (rev 03)
00:11.0 Host bridge: ServerWorks: Unknown device 0101 (rev 03)
00:11.2 Host bridge: ServerWorks: Unknown device 0101 (rev 03)
01:02.0 Multimedia video controller: PLD APPLICATIONS: Unknown device
5555 (rev 58)
01:03.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5703
Gigabit Ethernet (rev 02)
02:02.0 Multimedia video controller: PLD APPLICATIONS: Unknown device
5555 (rev 58)
02:03.0 Multimedia video controller: PLD APPLICATIONS: Unknown device
5555 (rev 58)
03:02.0 Multimedia video controller: PLD APPLICATIONS: Unknown device
5555 (rev 58)
04:03.0 SCSI storage controller: Adaptec AIC-7902 U320 (rev 03)
04:03.1 SCSI storage controller: Adaptec AIC-7902 U320 (rev 03)
