Hello,
I'm not sure who to address this Patch to either
It fixes a delay issue with CPM UART driver on Powerpc MPC8xx.
The problem is that with the actual code, the driver waits 32 IDLE patterns
before returning the received data to the upper level. It means for instance
about 1 second at 300 bauds.
This fix limits to one byte the waiting period.
Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
--- linux-3.5-vanilla/drivers/tty/serial/cpm_uart/cpm_uart_core.c
2012-07-21 22:58:29.000000000 +0200
+++ linux-3.5/drivers/tty/serial/cpm_uart/cpm_uart_core.c 2012-08-09
17:38:37.000000000 +0200
@@ -798,7 +799,7 @@
cpm_set_scc_fcr(sup);
out_be16(&sup->scc_genscc.scc_mrblr, pinfo->rx_fifosize);
- out_be16(&sup->scc_maxidl, pinfo->rx_fifosize);
+ out_be16(&sup->scc_maxidl, 1);
out_be16(&sup->scc_brkcr, 1);
out_be16(&sup->scc_parec, 0);
out_be16(&sup->scc_frmec, 0);
@@ -872,7 +873,7 @@
/* Using idle character time requires some additional tuning. */
out_be16(&up->smc_mrblr, pinfo->rx_fifosize);
- out_be16(&up->smc_maxidl, pinfo->rx_fifosize);
+ out_be16(&up->smc_maxidl, 1);
out_be16(&up->smc_brklen, 0);
out_be16(&up->smc_brkec, 0);
out_be16(&up->smc_brkcr, 1);
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