On 04/20/2013 11:26 AM, Frank Rizzo wrote: > On Fri, 19 Apr 2013 19:59:58 -0700, Yijing Wang <wangyijing@xxxxxxxxxx> wrote: > >> On 2013/4/20 10:22, Frank Rizzo wrote: >>> (with device powered on AFTER boot) >>> >>> root@frank-System-Product-Name:~# echo 1 > /sys/bus/pci/rescan >> >> Hi Frank, >> When you do rescan here, any new message info will print in dmesg? >> Compare the two lspci info, it seems like your external device is >> 02.0-[02]----00.0 Device 1a39:0004, which include a pci bridge and a pci endpoint device. >> But let me confused is that after you rescan (with device powered on AFTER boot), >> there is no any new device found, normally, at least we should found the bridge device. >> Maybe the link between host bridge and your external device got some problems? I am not sure. > > > Yijing, when powered on, the device works fine. I can talk to all the registers, and do everything that I need to do. This "late power-on issue" is the only thing holding me back. > > This is what I get in dmesg. (Cleared first) > > root@frank-System-Product-Name:~# dmesg -c > (SNIP!) > root@frank-System-Product-Name:~# echo 1 > /sys/bus/pci/rescan > root@frank-System-Product-Name:~# dmesg > [ 1180.917841] fglrx_pci 0000:01:05.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment > root@frank-System-Product-Name:~# > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html Hi Frank, I have a feeling that BIOS has done something bad here. According to a googled message as below, 00:00.0 Host bridge: Advanced Micro Devices [AMD] RS780 Host Bridge Alternate 00:01.0 PCI bridge: Advanced Micro Devices [AMD] RS780 PCI to PCI bridge (int gfx) 00:02.0 PCI bridge: Advanced Micro Devices [AMD] RS780 PCI to PCI bridge (ext gfx port 0) 00:05.0 PCI bridge: Advanced Micro Devices [AMD] RS780 PCI to PCI bridge (PCIE port 1) 00:06.0 PCI bridge: Advanced Micro Devices [AMD] RS780 PCI to PCI bridge (PCIE port 2) 00:11.0 SATA controller: ATI Technologies Inc SB700/SB800 SATA Controller [AHCI mode] 00:12.0 USB Controller: ATI Technologies Inc SB700/SB800 USB OHCI0 Controller 00:12.2 USB Controller: ATI Technologies Inc SB700/SB800 USB EHCI Controller 00:13.0 USB Controller: ATI Technologies Inc SB700/SB800 USB OHCI0 Controller 00:13.2 USB Controller: ATI Technologies Inc SB700/SB800 USB EHCI Controller Device 00:02.0 on AMD RS780 chipset should be a PCIe root port. But note here, seems it's specially designed for external graphics(ext gfx port 0). BIOS may disable this root port on boot if there's no device connected to this PCIe root port because it's for graphics. This explains why 00:02.0 even doesn't show up in the "with device powered on AFTER boot" case. You may try to plug the special adapter into another PCIe slot. It may also help to send out "lspci -v" messages with the device powered on boot. Thanks! Gerry -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
