From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <200007310911.KAA04511@hyperion.valhalla.net> Date: Mon, 31 Jul 2000 10:11:51 +0100 Subject: Re: Stealth port problems From: "Iain Sandoe" To: Giuliano Pochini CC: linuxppc-dev@lists.linuxppc.org Mime-version: 1.0 Content-type: text/plain; charset="US-ASCII" Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Mon, Jul 31, 2000, Giuliano Pochini wrote: >>> The problem is definitely X. I made a lot of tests: with dma and non-dma >>> serial driver, X accelerated, non accelerated, X bare.bone (started with >>> xinit). The problem is X. When X is running the serial ports looses packets >>> :-(( >>> Am I the only one who is having this problem ??? Why does X cause overruns >>> ?? > >> If you can try 2.2.17pre10ben2 or pre13ben2 (linuxcare linux-pmac-benh) then >> you can apply the IRQ latency test and see if it is that which is blocking >> you. Scan the dev list for "[ANN} IRQ". > > I'll try a soon I have a bit of free time... There's a pre-built kernel, modules & system.map (with IRQ latency & dmasound stuff already applied ) linked to: http://www.drfruitcake.com/linux/linuxppc.html The IRQh app - which you need to start the profiling is linked to : http://www.drfruitcake.com/linux/irq_blk.html >> The RX buffer in an 85230 (which is actually the chip - IIRC - an enhanced >> 8530) is 8 characters deep - so any more that about 700 us IRQ block will >> cause a drop out at 115200 continuous... > > On the Amiga I used to rtx stuff at 230K with no problems. It has 1 byte > buffer... BTW st SCC-XXdma stuff *is* enabled on my G3 by default. Iain. ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/