> The error in the log you attached does look very much like the sort of > thing we typically see with Genesys devices. The activity LED remaining > on just indicates that the controller has crashed. I have no idea why > writing and reading should behave any differently. Have you tried doing > large reads as well as large writes? > Large reads started to work really nicely after reducing max_sectors down to 128. Actually, the transfer rates I'm getting with reads are really nice.
> You can always try reducing that max_sectors value from the patch. Try > values below 64. The minimum is 8, and it's probably best to stick to > multiples of 8. > I've tried 64, 16 and 8. Neither works with writing. Reading gets slower, as is to be expected. Actually, looks like with the lower values of max_sectors disconnection of the USB cable resets the adapter -- red LED goes down. > It's not at all clear what goes wrong with the Genesys controllers. It > might be related to the speed of the data transfers; maybe it doesn't like > getting too much data too quickly. Oddly, most of the people with > problems like yours have found that max_sectors = 128 works. > I'm mot really familiar with the USB interface nuts and bolts, but it appears to me that what we see concerns more the transport layer (if it exists) than the usb-storage driver. The Genesis controller does not seem to cope either with too large data frames or with too frequent ones. Requesting less data while reading sort of fixes the problem by making the Genesis contoller to send less data at once. But it looks like the host controller (either on hardware or software level) is able to optimise the traffic by a sort of caching. So I guess that the host controller glues smaller data frames into bigger ones and the Genesis controller is not able to cope with them. Does this sound reasonable? The thing is that the device is fully functional under Win2k (I have a dual-boot setup, so all the hardware is exactly the same). It's a real pain for me as a linux fun to have it not running under my main OS :-(( I'm willing to help to track down the problem by providing all sorts of debug info. I'm rather fit with C/C++ to do certain things on my own, but never did anything on the kernel/device driver level. Just let me know what shell I do. Regards, Max ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
