[PATCH] serial/core.c: Unneeded memory barriers and cleanup

From: Felipe W Damasio
Date: Mon Sep 15 2003 - 09:59:38 EST


Hi Russell,

Patch against 2.6-test5.

Kills a unneeded set_current_state (TASK_RUNNING) after schedule_timeout and replaces a TASK_RUNNING settings with non-memory-barrier versions.

On uart_suspend_port, that set state thing isn't needed if schedule_timeout was executed..but I couldn't come up with a (clean) fix for that, since we need to execute ops->shutdown. So I just replace it with __set_current_state so It's just an attribution and it's not that expensive.

Feel free to tell me I screwed up :)

Thanks,

Felipe --- drivers/serial/core.c.orig 2003-09-15 11:49:50.000000000 -0300
+++ drivers/serial/core.c 2003-09-15 11:53:13.000000000 -0300
@@ -1022,7 +1022,7 @@
cprev = cnow;
}

- current->state = TASK_RUNNING;
+ __set_current_state(TASK_RUNNING);
remove_wait_queue(&state->info->delta_msr_wait, &wait);

return ret;
@@ -1277,7 +1277,6 @@
if (state->close_delay) {
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(state->close_delay);
- set_current_state(TASK_RUNNING);
}
} else if (!uart_console(port)) {
uart_change_pm(state, 3);
@@ -1345,11 +1344,11 @@
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(char_time);
if (signal_pending(current))
- break;
+ return;
if (time_after(jiffies, expire))
- break;
+ return;
}
- set_current_state(TASK_RUNNING); /* might not be needed */
+ __set_current_state(TASK_RUNNING); /* might not be needed */
}

/*
@@ -1480,7 +1479,7 @@
if (signal_pending(current))
break;
}
- set_current_state(TASK_RUNNING);
+ __set_current_state(TASK_RUNNING);
remove_wait_queue(&info->open_wait, &wait);

state->count++;
@@ -1899,7 +1898,7 @@
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(10*HZ/1000);
}
- set_current_state(TASK_RUNNING);
+ __set_current_state(TASK_RUNNING);

ops->shutdown(port);
}