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--- etc:users:jcmvbkbc:xtensa-linux [2011/06/24 22:58] – jcmvbkbc
+++ etc:users:jcmvbkbc:xtensa-linux [2016/08/08 20:53] (current) – ↷ Page moved from users:jcmvbkbc:xtensa-linux to etc:users:jcmvbkbc:xtensa-linux kel
@@ Line 120: / Line 120: @@
         retw                            # rotate back by 4 registers, possibly with underflow
                                         # Back out our _entry Frame above...
+</code>
+==== Random symbols appear like being typed on the console ====
+There's no checks for select simcall error status (or maybe there just should not be EINTR error, that's just not documented). Fix is the following:
+<code>
+diff --git a/arch/xtensa/platforms/iss/console.c b/arch/xtensa/platforms/iss/console.c
+index e650152..285744e 100644
+--- a/arch/xtensa/platforms/iss/console.c
++++ b/arch/xtensa/platforms/iss/console.c
+@@ -126,10 +126,11 @@ static void rs_poll(unsigned long priv)
+        spin_lock(&timer_lock);
+-       while (__simc(SYS_select_one, 0, XTISS_SELECT_ONE_READ, (int)&tv,0,0)){
+-               __simc (SYS_read, 0, (unsigned long)&c, 1, 0, 0);
+-               tty_insert_flip_char(tty, c, TTY_NORMAL);
+-               i++;
++       while (__simc(SYS_select_one, 0, XTISS_SELECT_ONE_READ, (int)&tv,0,0) > 0) {
++               if (__simc (SYS_read, 0, (unsigned long)&c, 1, 0, 0) == 1) {
++                       tty_insert_flip_char(tty, c, TTY_NORMAL);
++                       i++;
++               }
+        }
+        if (i)
+</code>
+==== Console is tooooo slooooow ====
+There's polling timer, it's 20 seconds :(). Fix is the following:
+<code>
+diff --git a/arch/xtensa/platforms/iss/console.c b/arch/xtensa/platforms/iss/console.c
+index e650152..285744e 100644
+--- a/arch/xtensa/platforms/iss/console.c
++++ b/arch/xtensa/platforms/iss/console.c
+@@ -35,7 +35,7 @@
+ #endif
+ #define SERIAL_MAX_NUM_LINES 1
+-#define SERIAL_TIMER_VALUE (20 * HZ)
++#define SERIAL_TIMER_VALUE (HZ / 10)
+ static struct tty_driver *serial_driver;
+ static struct timer_list serial_timer;
 </code>