Re: [PATCH] USB: add USB test and measurement class driver - round 2

From: Oliver Neukum
Date: Fri Aug 29 2008 - 03:45:36 EST


Am Freitag 29 August 2008 08:57:54 schrieb stefan_kopp@xxxxxxxxxxx:
> The issue with using cat on the shell level is that it uses fread which has the (in this case) ugly behaviour of recalling the driver's read method until the full number of characters requested has been accumulated (or until zero characters are returned, indicating the end of file). With USBTMC instruments, this behavour is bad because the retry

This may be problematic. The driver is throwing away EOF in other words.
Generally this is not a good idea. User space can no longer tell how long the
reply was.

Regards
Oliver

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