Title: [7389] trunk/drivers/spi/spi_bfin5xx.c: a minor optimization commented by Mike.
- Revision
- 7389
- Author
- bhsong
- Date
- 2009-09-20 22:39:27 -0400 (Sun, 20 Sep 2009)
Log Message
a minor optimization commented by Mike. the only places we use
chip->flag is in the active/deactive and enable/disable function.
based on the assumption that we will call active/deactive a lot more
than enable/disable (at the minimum, we'll call it the same number of
times), we can save FLG# instead of FLS#.
Modified Paths
Diff
Modified: trunk/drivers/spi/spi_bfin5xx.c (7388 => 7389)
--- trunk/drivers/spi/spi_bfin5xx.c 2009-09-21 02:27:43 UTC (rev 7388)
+++ trunk/drivers/spi/spi_bfin5xx.c 2009-09-21 02:39:27 UTC (rev 7389)
@@ -190,7 +190,7 @@
if (likely(chip->chip_select_num)) {
u16 flag = read_FLAG(drv_data);
- flag &= ~(chip->flag << 8);
+ flag &= ~chip->flag;
write_FLAG(drv_data, flag);
} else {
@@ -203,7 +203,7 @@
if (likely(chip->chip_select_num)) {
u16 flag = read_FLAG(drv_data);
- flag |= (chip->flag << 8);
+ flag |= chip->flag;
write_FLAG(drv_data, flag);
} else {
@@ -220,7 +220,7 @@
{
u16 flag = read_FLAG(drv_data);
- flag |= chip->flag;
+ flag |= (chip->flag >> 8);
write_FLAG(drv_data, flag);
}
@@ -229,7 +229,7 @@
{
u16 flag = read_FLAG(drv_data);
- flag &= ~chip->flag;
+ flag &= ~(chip->flag >> 8);
write_FLAG(drv_data, flag);
}
@@ -1259,7 +1259,7 @@
* SPI_BAUD, not the real baudrate
*/
chip->baud = hz_to_spi_baud(spi->max_speed_hz);
- chip->flag = 1 << (spi->chip_select);
+ chip->flag = (1 << (spi->chip_select)) << 8;
chip->chip_select_num = spi->chip_select;
switch (chip->bits_per_word) {
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