Hello Alan, Zitat von Alan Stern:
> On Tue, 9 Nov 2004, Dirk Kosch�tzki wrote: > > > In the last hours I investigated more on the data on the disks: If I write > > controlled data and try to compare it, then I can produce the problem > > under linux and windows and something interesting happens: > > > > Under Linux (2.6.9, unpatched) an IO error occurs in the application. > > After remounting the partition I can try to reread the file and every > > thing is ok. > > > > Under Windows it seems to me, that the system "buffers" the error. I see > > an entry in the event log, but the application did not see the error. > > > > Would it be possible to do the same in linux? I know, that this is a hack > > but maybe it is better than to throw an error ... > > I don't understand what you're asking. How is the operating system > supposed to respond to a READ operation when the device refuses to send > the data, except by telling the program that an error occurred? Well, actually I don't know. I see that under Windows there must be some kind of retry mechanism. The disk/controller/whatever signals an error, this error is recorded in the event log and afterwards some kind of retry occurs. In the result the correct buffer seems to be available for the application requesting it. Here is my procedure in detail: I created >20G of 1M files. Every file contains the same pattern: bytes from 0-255 in accending order. A second program tried to read these files sequentially and non-concurrently to the writer. Finally, I compared the result from the disk with the expected. With this test I see that Linux forwards the error to the application and that Windows has some kind of retry mechanism. My question is: is it possible to implement such a retry mechanism within the Linux USB subsystem? With kind regards, Dirk Ps.: My support request at Genesys Logic remained unanswered sofare. ------------------------------------------------------- This SF.Net email is sponsored by: Sybase ASE Linux Express Edition - download now for FREE LinuxWorld Reader's Choice Award Winner for best database on Linux. http://ads.osdn.com/?ad_idU88&alloc_id065&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
