On Wed, Feb 10, 2016 at 02:11:19PM +0100, Rainer Koenig wrote: > 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. The fifo size of what exactly? And as this is Intel's bug in their hardware, I suggest you work with them, there's not much here we can do about it, right? best of luck, greg k-h -- 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
