parisc: KittyHawk LCD fix

K class aka KittyHawk don't have LED support on their LCD. Installing
HP-UX confirmed this. The current led_wq fills the LCD with black
characters each time it runs.

The patch prevents the led_wq workqueue and its proc entry to be
created for KittyHawk machines.

It also increase min_cmd_delay as currently, one character out of two
is lost when a string is sent to the LCD.

Signed-off-by: Guy Martin <gmsoft@tuxicoman.be>
Signed-off-by: Kyle McMartin <kyle@mcmartin.c>

1 files changed, 13 insertions, 4 deletions

diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c
index 2350e8a86eef..f2f501e5b6a0 100644
--- a/drivers/parisc/led.c
+++ b/drivers/parisc/led.c
@@ -64,6 +64,7 @@ static unsigned int led_diskio    __read_mostly = 1;
 static unsigned int led_lanrxtx   __read_mostly = 1;
 static char lcd_text[32]          __read_mostly;
 static char lcd_text_default[32]  __read_mostly;
+static int  lcd_no_led_support    __read_mostly = 0; /* KittyHawk doesn't support LED on its LCD */
 
 
 static struct workqueue_struct *led_wq;
@@ -115,7 +116,7 @@ lcd_info __attribute__((aligned(8))) __read_mostly =
         .lcd_width =            16,
         .lcd_cmd_reg_addr =     KITTYHAWK_LCD_CMD,
         .lcd_data_reg_addr =    KITTYHAWK_LCD_DATA,
-        .min_cmd_delay =        40,
+        .min_cmd_delay =        80,
         .reset_cmd1 =           0x80,
         .reset_cmd2 =           0xc0,
 };
@@ -135,6 +136,9 @@ static int start_task(void)
         /* Display the default text now */
         if (led_type == LED_HASLCD) lcd_print( lcd_text_default );
 
+        /* KittyHawk has no LED support on its LCD */
+        if (lcd_no_led_support) return 0;
+
         /* Create the work queue and queue the LED task */
         led_wq = create_singlethread_workqueue("led_wq");       
         queue_delayed_work(led_wq, &led_task, 0);
@@ -248,9 +252,13 @@ static int __init led_create_procfs(void)
 
         proc_pdc_root = proc_mkdir("pdc", 0);
         if (!proc_pdc_root) return -1;
-        ent = proc_create_data("led", S_IRUGO|S_IWUSR, proc_pdc_root,
-                                &led_proc_fops, (void *)LED_NOLCD); /* LED */
-        if (!ent) return -1;
+
+        if (!lcd_no_led_support)
+        {
+                ent = proc_create_data("led", S_IRUGO|S_IWUSR, proc_pdc_root,
+                                        &led_proc_fops, (void *)LED_NOLCD); /* LED */
+                if (!ent) return -1;
+        }
 
         if (led_type == LED_HASLCD)
         {
@@ -692,6 +700,7 @@ int __init led_init(void)
         case 0x58B:             /* KittyHawk DC2 100 (K200) */
                 printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
                                 "LED detection skipped.\n", __FILE__, CPU_HVERSION);
+                lcd_no_led_support = 1;
                 goto found;     /* use the preinitialized values of lcd_info */
         }