On Jun 15,  7:25pm, srp@tworoads.net (srp@tworoads.net) wrote:
-- Subject: kern/33742: Multiple bktr cards and changing PCI latency.

| >Number:         33742
| >Category:       kern
| >Synopsis:       multiple bktr cards may require change in PCI latency.
| >Confidential:   no
| >Severity:       non-critical
| >Priority:       low
| >Responsible:    kern-bug-people
| >State:          open
| >Class:          change-request
| >Submitter-Id:   net
| >Arrival-Date:   Thu Jun 15 19:25:00 +0000 2006
| >Originator:     Scott Presnell
| >Release:        NetBSD 3.0_STABLE
| >Organization:
| 	Self
| >Environment:
| 
| NetBSD 3.0_STABLE (SKOK) #4: Thu Jun 15 08:30:40 PDT 2006
| 	srp@dirt.tworoads.net:/usr/src/sys/arch/i386/compile/SKOK
| 
| Architecture: i386
| Machine: i386
| 
| >Description:
| 
| I use a webcam to monitor a remote location.  Recently I added a second
| camera and second WinTV (bktr driver) card, but when I did one of the cards
| started acting as though it was not getting a full frame capture, when
| running in continuous capture mode (seemed to work OK when single capture
| mode was used).
| 
| After checking the software and other possible souces of error, I
| discovered that the manufacturer had in the past recommended reducing
| the PCI latency under similar circumstances
| 
| (http://www.hauppauge.com/html/sw_wcst.htm) 
| 
| ...so I tried this first as a hack, it seemed to work, then rewrote it as a
| bktr driver kernel option.  A latency value of 0x10 worked in my case.
| 
| >How-To-Repeat:
| 
| Find an old 180 MHz Pentium pro, install two bktr cards, start capturing in
| continuous mode (a program called camserv was used).
| 
| NetBSD 3.0_STABLE (SKOK) #4: Thu Jun 15 08:30:40 PDT 2006
| 	srp@dirt.tworoads.net:/usr/src/sys/arch/i386/compile/SKOK
| total memory = 127 MB
| avail memory = 120 MB
| BIOS32 rev. 0 found at 0xffe90
| mainbus0 (root)
| cpu0 at mainbus0: (uniprocessor)
| cpu0: Intel Pentium Pro (686-class), 179.64 MHz, id 0x619
| cpu0: features fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR>
| cpu0: features fbff<PGE,MCA,CMOV>
| cpu0: I-cache 8 KB 32B/line 4-way, D-cache 8 KB 32B/line 2-way
| cpu0: L2 cache 256 KB 32B/line 4-way
| cpu0: ITLB 32 4 KB entries 4-way, 2 4 MB entries fully associative
| cpu0: DTLB 64 4 KB entries 4-way, 8 4 MB entries 4-way
| cpu0: 16 page colors
| pci0 at mainbus0 bus 0: configuration mode 1
| pci0: i/o space, memory space enabled, rd/line, rd/mult, wr/inv ok
| pchb0 at pci0 dev 0 function 0
| pchb0: Intel 82441FX (PMC) PCI and Memory Controller (rev. 0x02)
| pcib0 at pci0 dev 13 function 0
| pcib0: Intel 82371SB (PIIX3) PCI-ISA Bridge (rev. 0x01)
| piixide0 at pci0 dev 13 function 1
| piixide0: Intel 82371SB IDE Interface (PIIX3) (rev. 0x00)
| piixide0: bus-master DMA support present
| piixide0: primary channel wired to compatibility mode
| piixide0: primary channel interrupting at irq 14
| atabus0 at piixide0 channel 0
| piixide0: secondary channel wired to compatibility mode
| piixide0: secondary channel interrupting at irq 15
| atabus1 at piixide0 channel 1
| uhci0 at pci0 dev 13 function 2: Intel 82371SB (PIIX3) USB Host Controller (rev. 0x01)
| uhci0: interrupting at irq 11
| usb0 at uhci0: USB revision 1.0
| uhub0 at usb0
| uhub0: Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
| uhub0: 2 ports with 2 removable, self powered
| ppb0 at pci0 dev 14 function 0: Digital Equipment DC21052 PCI-PCI Bridge (rev. 0x01)
| pci1 at ppb0 bus 1
| pci1: i/o space, memory space enabled, rd/line, wr/inv ok
| ex0 at pci1 dev 8 function 0: 3Com 3c905-TX 10/100 Ethernet (rev. 0x0)
| ex0: interrupting at irq 11
| ex0: MAC address 00:c0:4f:b6:af:9e
| exphy0 at ex0 phy 24: 3Com internal media interface
| exphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
| bktr0 at pci1 dev 9 function 0
| bktr0: interrupting at irq 11
| bktr0: Hauppauge Model 38101 B410
| bktr0: Hauppauge WinCast/TV, Philips NTSC tuner.
| Brooktree Bt878 Video Capture (Audio Section) (miscellaneous multimedia, revision 0x11) at pci1 dev 9 function 1 not configured
| vga1 at pci0 dev 16 function 0: S3 Trio32/64 (rev. 0x54)
| wsdisplay0 at vga1 kbdmux 1: console (80x25, vt100 emulation)
| wsmux1: connecting to wsdisplay0
| bktr1 at pci0 dev 17 function 0
| bktr1: interrupting at irq 10
| bktr1: Hauppauge Model 44801 C110
| bktr1: Hauppauge WinCast/TV, Philips NTSC tuner.
| Brooktree Bt878 Video Capture (Audio Section) (miscellaneous multimedia, revision 0x11) at pci0 dev 17 function 1 not configured
| isa0 at pcib0
| lpt0 at isa0 port 0x378-0x37b irq 7
| com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
| com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
| com2 at isa0 port 0x3e8-0x3ef irq 5: ns16550a, working fifo
| pckbc0 at isa0 port 0x60-0x64
| pckbd0 at pckbc0 (kbd slot)
| pckbc0: using irq 1 for kbd slot
| wskbd0 at pckbd0: console keyboard, using wsdisplay0
| pcppi0 at isa0 port 0x61
| sysbeep0 at pcppi0
| isapnp0 at isa0 port 0x279: ISA Plug 'n Play device support
| npx0 at isa0 port 0xf0-0xff: using exception 16
| fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
| isapnp0: no ISA Plug 'n Play devices found
| fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec
| ulpt0 at uhub0 port 1 configuration 1 interface 0
| ulpt0: HewLett Packard HP LaserJet 1200, rev 1.10/1.00, addr 2, iclass 7/1
| ulpt0: using bi-directional mode
| ugen0 at uhub0 port 2
| ugen0: American Power Conversion Back-UPS NS 1050 FW:7.g3 .D USB FW:g3, rev 1.10/1.06, addr 3
| wd0 at atabus0 drive 0: <WDC AC22100H>
| wd0: drive supports 16-sector PIO transfers, LBA addressing
| wd0: 2014 MB, 4092 cyl, 16 head, 63 sec, 512 bytes/sect x 4124736 sectors
| wd0: 32-bit data port
| wd0: drive supports PIO mode 4, DMA mode 2
| wd0(piixide0:0:0): using PIO mode 4, DMA mode 2 (using DMA)
| atapibus0 at atabus1: 2 targets
| cd0 at atapibus0 drive 0: <NEC                 CD-ROM DRIVE:282, , 3.07> cdrom removable
| cd0: 32-bit data port
| cd0: drive supports PIO mode 3, DMA mode 1
| cd0(piixide0:1:0): using PIO mode 0, DMA mode 1 (using DMA)
| boot device: wd0
| root on wd0a dumps on wd0b
| root file system type: ffs
| wsdisplay0: screen 1 added (80x25, vt100 emulation)
| wsdisplay0: screen 2 added (80x25, vt100 emulation)
| wsdisplay0: screen 3 added (80x25, vt100 emulation)
| wsdisplay0: screen 4 added (80x25, vt100 emulation)
| 
| >Fix:
| 
| 
| The following patch adds BKTR_OVERRIDE_LATENCY as a kernel option
| for the bktr driver.
| 
| --- sys/dev/pci/files.pci.orig	2006-06-15 08:07:56.000000000 -0700
| +++ sys/dev/pci/files.pci	2006-06-15 08:08:57.000000000 -0700
| @@ -10,7 +10,7 @@
|  defflag	opt_bktr.h	BKTR_430_FX_MODE BKTR_GPIO_ACCESS BKTR_NO_MSP_RESET
|  			BKTR_REVERSE_MUTE BKTR_SIS_VIA_MODE BKTR_USE_PLL
|  defparam opt_bktr.h	BKTR_OVERRIDE_CARD BKTR_OVERRIDE_TUNER BKTR_OVERRIDE_DBX
| -			BKTR_OVERRIDE_MSP BKTR_SYSTEM_DEFAULT
| +			BKTR_OVERRIDE_MSP BKTR_OVERRIDE_LATENCY BKTR_SYSTEM_DEFAULT
|  
|  defflag	opt_pciide.h	PCIIDE_CMD064x_DISABLE PCIIDE_AMD756_ENABLEDMA
|  			PCIIDE_CMD0646U_ENABLEUDMA PCIIDE_I31244_DISABLEDMA
| --- sys/dev/pci/bktr/bktr_os.c.orig	2006-06-15 10:38:53.000000000 -0700
| +++ sys/dev/pci/bktr/bktr_os.c	2006-06-15 08:29:41.000000000 -0700
| @@ -1520,18 +1520,33 @@
|  #ifndef BROOKTREE_DEF_LATENCY_VALUE
|  #define BROOKTREE_DEF_LATENCY_VALUE	0x10
|  #endif
| +
| +	latency = pci_conf_read(pa->pa_pc, pa->pa_tag, PCI_LATENCY_TIMER);
| +	latency = (latency >> 8) & 0xff;
| +
| +#if defined(BKTR_OVERRIDE_LATENCY)
| +
| +	printf("%s: overriding PCI bus latency was %d changing to %d\n",
| +	       bktr_name(bktr), (int) latency, BKTR_OVERRIDE_LATENCY);
| +	latency = BKTR_OVERRIDE_LATENCY;
| +	pci_conf_write(pa->pa_pc, pa->pa_tag,
| +		       PCI_LATENCY_TIMER, latency<<8);
| +
| +#else
| +	
|  	latency = pci_conf_read(pa->pa_pc, pa->pa_tag, PCI_LATENCY_TIMER);
|  	latency = (latency >> 8) & 0xff;
|  
|  	if (!latency) {
|  		if (bootverbose) {
| -			printf("%s: PCI bus latency was 0 changing to %d",
| +			printf("%s: PCI bus latency was 0 changing to %d\n",
|  			       bktr_name(bktr), BROOKTREE_DEF_LATENCY_VALUE);
|  		}
|  		latency = BROOKTREE_DEF_LATENCY_VALUE;
|  		pci_conf_write(pa->pa_pc, pa->pa_tag,
|  			       PCI_LATENCY_TIMER, latency<<8);
|  	}
| +#endif
|  
|  	common_bktr_attach(bktr, unit, pa->pa_id, PCI_REVISION(pa->pa_class));
|  
| ===
| 
| The resulting dmesg changes when using 
| 
| options BKTR_OVERRIDE_LATENCY 0x10
| 

What are the valid values of latency? Shouldn't the driver check for those?

christos