Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-16 16:12:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

serial: sh-sci: Improve comments for DMA timeout calculation

Browse Source 
Reformat, grammar improvements, use "ms" instead of "msec".

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Geert Uytterhoeven 2015-08-21 20:02:38 +02:00 committed by Greg Kroah-Hartman
parent beb9487b0c
commit f5835c1d0e
1 changed files with 7 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/tty/serial/sh-sci.c
View File

@ -2015,13 +2015,13 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
#ifdef CONFIG_SERIAL_SH_SCI_DMA #ifdef CONFIG_SERIAL_SH_SCI_DMA
/* /*
* Calculate delay for 2 DMA buffers (4 FIFO). * Calculate delay for 2 DMA buffers (4 FIFO).
* See serial_core.c::uart_update_timeout(). With 10 * See serial_core.c::uart_update_timeout().
* bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above function * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
* calculates 1 jiffie for the data plus 5 jiffies for the "slop(e)." * function calculates 1 jiffie for the data plus 5 jiffies for the
* Then below we calculate 5 jiffies (20ms) for 2 DMA buffers (4 FIFO * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
* sizes), but when performing a faster transfer, value obtained by * buffers (4 FIFO sizes), but when performing a faster transfer, the
* this formula is may not enough. Therefore, if value is smaller than * value obtained by this formula is too small. Therefore, if the value
* 20msec, this sets 20msec as timeout of DMA. * is smaller than 20ms, use 20ms as the timeout value for DMA.
*/ */
if (s->chan_rx) { if (s->chan_rx) {
unsigned int bits; unsigned int bits;