arm:rs232 fix.

The kernel API for requesting interrupts and the associated callback
have a somewhat strange behaviour. Requesting an interrupts is done
by calling sys_irqsetpolicy using an interrupt and a given id. This
id can be modified by the sys_irqsetpolicy and must be used for
subsequent calls to sys_irqenable/sys_irqdisable. However upon an
incoming call from the kernel NOTIFY_ARG contains the original value
encoded in a set e.g. if  1 << id == true the interrupt was raised.

diff --git a/drivers/tty/arch/earm/rs232.c b/drivers/tty/arch/earm/rs232.c
index 3a3b256bd711129481ab6916169f4a7a3f3e1de0..fc3a9734c86aba6b1519b854916cb947807bf982 100644 (file)
--- a/drivers/tty/arch/earm/rs232.c
+++ b/drivers/tty/arch/earm/rs232.c
@@ -108,6 +108,7 @@ typedef struct rs232 {
 
   int irq;                     /* irq for this line */
   int irq_hook_id;             /* interrupt hook */
+  int irq_hook_kernel_id;      /* id as returned from sys_irqsetpolicy */
 
   char ibuf[RS_IBUFSIZE];      /* input buffer */
   char obuf[RS_OBUFSIZE];      /* output buffer */
@@ -428,7 +429,7 @@ static void rs_config(rs232_t *rs)
         * avoid looping forever.
         */
 
-       if (sys_irqdisable(&rs->irq_hook_id) != OK)
+       if (sys_irqdisable(&rs->irq_hook_kernel_id) != OK)
                panic("unable to disable interrupts");
 
        /* Select the baud rate divisor registers and change the rate. */
@@ -456,7 +457,7 @@ static void rs_config(rs232_t *rs)
        if ((tp->tty_termios.c_lflag & IXON) && rs->oxoff != _POSIX_VDISABLE)
                rs->ostate &= ~ORAW;
        (void) serial_in(rs, OMAP3_IIR);
-       if (sys_irqenable(&rs->irq_hook_id) != OK)
+       if (sys_irqenable(&rs->irq_hook_kernel_id) != OK)
                panic("unable to enable interrupts");
 }
 
@@ -519,16 +520,27 @@ rs_init(tty_t *tp)
 
        /* Configure IRQ */
        rs->irq = this_omap3.irq;
-       rs->irq_hook_id = 1 << line;    /* call back with irq line number */
-       if (sys_irqsetpolicy(rs->irq, 0, &rs->irq_hook_id) != OK) {
+
+       /* callback with irq line number + 1 because using line number 0 
+          fails eslewhere */
+       rs->irq_hook_kernel_id = rs->irq_hook_id = line + 1;    
+
+       /* sys_irqsetpolicy modifies irq_hook_kernel_id. this modified id
+        * needs to be used in sys_irqenable and similar calls.
+        */
+       if (sys_irqsetpolicy(rs->irq, 0, &rs->irq_hook_kernel_id) != OK) {
                printf("RS232: Couldn't obtain hook for irq %d\n", rs->irq);
        } else {
-               if (sys_irqenable(&rs->irq_hook_id) != OK)  {
+               if (sys_irqenable(&rs->irq_hook_kernel_id) != OK)  {
                        printf("RS232: Couldn't enable irq %d (hooked)\n",
                                rs->irq);
                }
        }
-       rs_irq_set |= (1 << (rs->irq_hook_id + 1));
+
+       /* When we get called back we get called back using the original 
+        * hook_id bit set. e.g. if we register with hook_id 5 the callback
+        * calls us with the 5 th bit set */
+       rs_irq_set |= (1 << (rs->irq_hook_id ));
 
        /* Enable interrupts */
        rs_reset(rs);
@@ -559,9 +571,9 @@ rs_interrupt(message *m)
 
        irq_set = m->NOTIFY_ARG;
        for (line = 0, rs = rs_lines; line < NR_RS_LINES; line++, rs++) {
-               if (irq_set & (1 << (rs->irq_hook_id+1))) {
+               if (irq_set & (1 << rs->irq_hook_id)) {
                        rs232_handler(rs);
-                       if (sys_irqenable(&rs->irq_hook_id) != OK)
+                       if (sys_irqenable(&rs->irq_hook_kernel_id) != OK)
                                panic("unable to enable interrupts");
                }
        }