Hello, I have a Qt-based application which reads events from a Linux input device through /dev/input/eventX. The device I have is an USB barcode scanner, which works just like a keyboard. Unfortunately, I sometimes lose events coming from this USB barcode scanner, and I'm worried about the size of the in-kernel buffer for events. The USB barcode scanner acts like a keyboard, but sends events much, much faster. For example, when it scans a barcode such as "AZERTYUIOP1234", it generates the Shift press, key press, key release, Shift release for every character, generating at least 56 events in a row, very quickly (and the kernel only buffers 64 events if I'm correct). There are even worse cases: I have an USB barcode reader which is connected by Bluetooth with the barcode reader itself. When the barcode reader is far away from the base station, it just buffers the scanned barcodes, and when the barcode reader is again within the Bluetooth range from the base station, it sends all the buffered scanned barcode in a row. Potentially hundreds and hundreds of Linux input events coming in. Shouldn't the in-kernel buffer be larger for such devices, in order to leave more time for the applications to come and fetch the events ? As far as I could see, it doesn't seem to be possible to adjust the size of the in-kernel buffer from userspace (through some ioctl() call, for example). Did I miss something ? Thanks, Thomas -- Thomas Petazzoni, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
