>> It seems that the problem lies on the gs_buf_space_available(), more >> specifically related to that "-1" you added, I believe, to report >> "correctly" when you have an empty buffer, since: >> >> (buf_size + buf_get - buf_put) % buf_size >> >> would return 0 on that situation. > That's fairly standard for ring buffers; it avoids an extra > state varible to distinguish whether "both pointers are the > same" means empty or full. That simplifies the logic. The other way to do it, when buf_size is a power of 2 (as it is in this case), is to have get and put *offsets* (not pointers) which count mod UINT_MAX, and you mask them mod WRITE_BUF_SIZE (== 8192) before indexing into the buffer. That lets you use every byte in the buffer. (You can do it with non-power-of-2 buffers actually, but you have to have the offsets operate mod 2*buf_size and it gets a bit more intricate.) One thing I wonder is why have a run-time buf_size variable if its value is always a compile-time constant... -- 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
