Thank you for the reply >> The tty layer is limiting you, just keep reading in a loop until you >> run out of data, you should not ever expect to read a specific number of >> bytes from a tty device at a time, the read call will tell you the >> number that was read properly. I tried this method but in my case I found data loss. By changing any buffer size modification in driver side , can we fix this issue ? >> Please don't use the "generic" driver, it's slow and not the best to >> use Could you tell me is generic driver is suitable for my application ( My usb device sending data at a rate of 409600 bytes/sec) , ? or do you have any other suggestion for me ? My Linux kernel version is 3.4.35 Regards, Arun On Tue, Aug 4, 2015 at 1:13 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Mon, Aug 03, 2015 at 04:44:07PM +0900, arun k wrote: > > Hi , > > > > I have a trouble with using usb serial generic device. > > I am using USB - Generic Serial driver for communicating with my usb > > device and my embedded device. > > Please don't use the "generic" driver, it's slow and not the best to > use. > > > My usb device sending data at a rate of 409600 bytes/sec, and in host > > side application I tried to read 16384 bytes in one read. But the read > > size returning is always 4095 > > The tty layer is limiting you, just keep reading in a loop until you > run out of data, you should not ever expect to read a specific number of > bytes from a tty device at a time, the read call will tell you the > number that was read properly. > > thanks, > > greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html