From 31f6bd7fad3b149a1eb6f67fc2e742e4df369b3d Mon Sep 17 00:00:00 2001 From: Ilpo Järvinen Date: Mon, 25 Apr 2022 17:33:58 +0300 Subject: serial: Store character timing information to uart_port MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Struct uart_port currently stores FIFO timeout. Having character timing information readily available is useful. Even serial core itself determines char_time from port->timeout using inverse calculation. Store frame_time directly into uart_port. Character time is stored in nanoseconds to have reasonable precision with high rates. To avoid overflow, 64-bit math is necessary. It might be possible to determine timeout from frame_time by multiplying it with fifosize as needed but only part of the users seem to be protected by a lock. Thus, this patch does not pursue storing only frame_time in uart_port. Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220425143410.12703-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- include/linux/serial_core.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index d4828e69087a..cbd5070bc87f 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -232,6 +232,7 @@ struct uart_port { int hw_stopped; /* sw-assisted CTS flow state */ unsigned int mctrl; /* current modem ctrl settings */ unsigned int timeout; /* character-based timeout */ + unsigned int frame_time; /* frame timing in ns */ unsigned int type; /* port type */ const struct uart_ops *ops; unsigned int custom_divisor; -- cgit v1.2.3