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| author | Sonic Zhang <sonic.zhang@analog.com> | 2010-10-16 18:22:34 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-10-22 10:20:11 -0700 |
| commit | 0dd25df1a4e63c078f357aaffb09789c9438378f (patch) | |
| tree | e1ae2b79738420bb7b3150e0c156c1cc181d998c /drivers/serial | |
| parent | af7f3743567e3d5b40e2f9c21541b7f40b99c103 (diff) | |
| download | op-kernel-dev-0dd25df1a4e63c078f357aaffb09789c9438378f.zip op-kernel-dev-0dd25df1a4e63c078f357aaffb09789c9438378f.tar.gz | |
serial: bfin_sport_uart: speed up sport RX sample rate to be 3% faster
The actual uart baud rate of devices vary between +/-2% of what is
asked. The SPORT RX sample rate should be faster than double of the
worst case. Otherwise, wrong data may be received. So set SPORT RX
clock to be 3% faster in general.
Reported-by: Olivier STOCK <ostockemer@ereca.fr>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/serial')
| -rw-r--r-- | drivers/serial/bfin_sport_uart.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/serial/bfin_sport_uart.c b/drivers/serial/bfin_sport_uart.c index 5318dd3..6f1b51e2 100644 --- a/drivers/serial/bfin_sport_uart.c +++ b/drivers/serial/bfin_sport_uart.c @@ -131,7 +131,12 @@ static int sport_uart_setup(struct sport_uart_port *up, int size, int baud_rate) pr_debug("%s RCR1:%x, RCR2:%x\n", __func__, SPORT_GET_RCR1(up), SPORT_GET_RCR2(up)); tclkdiv = sclk / (2 * baud_rate) - 1; - rclkdiv = sclk / (2 * baud_rate * 2) - 1; + /* The actual uart baud rate of devices vary between +/-2%. The sport + * RX sample rate should be faster than the double of the worst case, + * otherwise, wrong data are received. So, set sport RX clock to be + * 3% faster. + */ + rclkdiv = sclk / (2 * baud_rate * 2 * 97 / 100) - 1; SPORT_PUT_TCLKDIV(up, tclkdiv); SPORT_PUT_RCLKDIV(up, rclkdiv); SSYNC(); |
