Re: Stealth port problems
From: Iain Sandoe <hidden>
Date: 2000-07-31 09:11:51
On Mon, Jul 31, 2000, Giuliano Pochini wrote:
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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 ??quoted
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
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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/