Hi there, I'm fighting with a tricky problem. I want to use a serial console, but not a usual one, the "serial controller" is the Intel AMT Serial Port Redirection. So I have the following PCI device: 00:16.3 Serial controller: Intel Corporation Sunrise Point-H KT Redirection (rev 31) (prog-if 02 [16550]) Subsystem: Fujitsu Technology Solutions Device 121d Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin D routed to IRQ 19 Region 0: I/O ports at f0a0 [size=8] Region 1: Memory at f704d000 (32-bit, non-prefetchable) [size=4K] Capabilities: [40] MSI: Enable- Count=1/1 Maskable- 64bit+ Address: 0000000000000000 Data: 0000 Capabilities: [50] Power Management version 3 Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-) Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME- Kernel driver in use: serial On an remote PC I use the "gamt" or "amtterm" to connect. Everything is fine on older systems with AMT versions < 11. But now we have new systems with AMT version 11 and the interface behaves somewhat strange. Strange means, I have to type 8 characters on my keyboard on the amtterm machine until they are echoed back from the machine running the serial port redirection. I sniffed on the LAN using wireshark and saw that every keystroke is immediately sent to the AMT machine, but it looks like AMT is now buffering 8 characters. Totally weird and not usable in a serial console context. We reported this to Intel and Intel said they are aware of this and this can be fixed by adjusting the FIFO size. They sent some fancy screenshot how to do this in Windows, but I need a solution for the Linux kernel. So questions: - Is there a way to change settings during runtime? I tried setserial but no luck, just get "device busy" responses. - If not I could think about patching the serial driver so that it checks if the device-ID is the one of the redirection device and then hard coded sets the receive FIFO size to 1. But even if such a patch would enter the mainline kernel it would take months until it hits the distributions... Thanks, Rainer-- Dipl.-Inf. (FH) Rainer Koenig Project Manager Linux Clients Dept. PDG WPS R&D SW OSE Fujitsu Technology Solutions Bürgermeister-Ullrich-Str. 100 86199 Augsburg Germany Telephone: +49-821-804-3321 Telefax: +49-821-804-2131 Mail: mailto:Rainer.Koenig@xxxxxxxxxxxxxx Internet ts.fujtsu.com Company Details ts.fujitsu.com/imprint.html -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
