Hi Roman: Am 03.02.10 07:16 schrieb(en) Roman Fietze:
Sorry for the delay ... your mail got stuck in a Notes "spam filter".
Never mind. I didn't know yet that I'm *such* a nasty guy... ;-)
Are you using MWDMA2 with the compact flash cards? What is the load on the different (DMA) channels? ATA reads or writes?
Actually, I forgot that I have to explicitly enable libata dma on the 5200b, due to the known silicon bugs... I will repeat my tests with the proper configuration, stay tuned.
... a signal processor attached to the localbus, using bestcomm and the fifo for the bulk transferAre you using an own driver, or are you using Grant's SCLPC+SDMA driver? BD task?
Basically Grant's driver, but with a slightly modified variant of the gen_bd task. The signal processor is a LE, and I managed to insert the LE/BE conversion into the bestcomm task (see also <http://patchwork.ozlabs.org/patch/35038/>). Unfortunately, there is no good documentation of the engine; I would like to also shift crc calculation into bestcomm, which seems to be possible in principle, but I never got it running.
The best thing is to run very ugly tests with very high load for at least 24h.
Thanks again for this tip! I hope I manage to run a test over the weekend. Throughput onto the cf cards is not critical for me (so I could live with pio there), but I'm a little afraid I might also see similar effects with fec and the signal processor (in particular, the latter *is* critical). Thanks, Albrecht.
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