[PATCH 1/2] RTC driver init adjustment

[PATCH 1/2] RTC driver init adjustment

[Jan Beulich]

This patch
- conditionalizes procfs code upon CONFIG_PROC_FS (to reduce code size when
  that option is not enabled)
- makes initialization no longer fail when the procfs entry can't be allocated
  (namely would initialization always have failed when CONFIG_PROC_FS was not
  set)
- moves the formerly file-scope static variable rtc_int_handler_ptr into the
  only function using it, and makes it automatic.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

--- linux-2.6.19/drivers/char/rtc.c	2006-12-08 13:03:35.000000000 +0100
+++ 2.6.19-rtc-cleanup/drivers/char/rtc.c	2006-12-08 13:07:42.000000000 +0100
@@ -113,7 +113,7 @@ static int rtc_has_irq = 1;
 #define hpet_set_rtc_irq_bit(arg) 		0
 #define hpet_rtc_timer_init() 			do { } while (0)
 #define hpet_rtc_dropped_irq() 			0
-static inline irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id) {return 0;}
+static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id) {return 0;}
 #else
 extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);
 #endif
@@ -165,7 +165,9 @@ static void mask_rtc_irq_bit(unsigned ch
 }
 #endif
 
+#ifdef CONFIG_PROC_FS
 static int rtc_proc_open(struct inode *inode, struct file *file);
+#endif
 
 /*
  *	Bits in rtc_status. (6 bits of room for future expansion)
@@ -906,6 +908,7 @@ static struct miscdevice rtc_dev = {
 	.fops		= &rtc_fops,
 };
 
+#ifdef CONFIG_PROC_FS
 static const struct file_operations rtc_proc_fops = {
 	.owner = THIS_MODULE,
 	.open = rtc_proc_open,
@@ -913,14 +916,13 @@ static const struct file_operations rtc_
 	.llseek = seq_lseek,
 	.release = single_release,
 };
-
-#if defined(RTC_IRQ) && !defined(__sparc__)
-static irq_handler_t rtc_int_handler_ptr;
 #endif
 
 static int __init rtc_init(void)
 {
+#ifdef CONFIG_PROC_FS
 	struct proc_dir_entry *ent;
+#endif
 #if defined(__alpha__) || defined(__mips__)
 	unsigned int year, ctrl;
 	char *guess = NULL;
@@ -932,9 +934,11 @@ static int __init rtc_init(void)
 	struct sparc_isa_bridge *isa_br;
 	struct sparc_isa_device *isa_dev;
 #endif
-#endif
-#ifndef __sparc__
+#else
 	void *r;
+#ifdef RTC_IRQ
+	irq_handler_t rtc_int_handler_ptr;
+#endif
 #endif
 
 #ifdef __sparc__
@@ -1024,17 +1028,13 @@ no_irq:
 		return -ENODEV;
 	}
 
+#ifdef CONFIG_PROC_FS
 	ent = create_proc_entry("driver/rtc", 0, NULL);
-	if (!ent) {
-#ifdef RTC_IRQ
-		free_irq(RTC_IRQ, NULL);
-		rtc_has_irq = 0;
+	if (ent)
+		ent->proc_fops = &rtc_proc_fops;
+	else
+		printk(KERN_WARNING "rtc: Failed to register with procfs.\n");
 #endif
-		release_region(RTC_PORT(0), RTC_IO_EXTENT);
-		misc_deregister(&rtc_dev);
-		return -ENOMEM;
-	}
-	ent->proc_fops = &rtc_proc_fops;
 
 #if defined(__alpha__) || defined(__mips__)
 	rtc_freq = HZ;
@@ -1167,6 +1167,7 @@ static void rtc_dropped_irq(unsigned lon
 }
 #endif
 
+#ifdef CONFIG_PROC_FS
 /*
  *	Info exported via "/proc/driver/rtc".
  */
@@ -1251,6 +1252,7 @@ static int rtc_proc_open(struct inode *i
 {
 	return single_open(file, rtc_proc_show, NULL);
 }
+#endif
 
 void rtc_get_rtc_time(struct rtc_time *rtc_tm)
 {

[PATCH 1/2] RTC driver init adjustment

[Jan Beulich]

Ensure RTC driver doesn't use its timer when it doesn't get to set it up (as
it cannot currently prevent other of its functions to be called from outside
when not built as a module - probably this should also be addressed).

Signed-off-by: Jan Beulich <jbeulich@novell.com>

--- linux-2.6.19/drivers/char/rtc.c	2006-11-29 22:57:37.000000000 +0100
+++ 2.6.19-rtc-no-irq/drivers/char/rtc.c	2006-12-08 13:03:35.000000000 +0100
@@ -958,6 +958,7 @@ static int __init rtc_init(void)
 		}
 	}
 #endif
+	rtc_has_irq = 0;
 	printk(KERN_ERR "rtc_init: no PC rtc found\n");
 	return -EIO;
 
@@ -972,6 +973,7 @@ found:
 	 * PCI Slot 2 INTA# (and some INTx# in Slot 1).
 	 */
 	if (request_irq(rtc_irq, rtc_interrupt, IRQF_SHARED, "rtc", (void *)&rtc_port)) {
+		rtc_has_irq = 0;
 		printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq);
 		return -EIO;
 	}
@@ -982,6 +984,9 @@ no_irq:
 	else
 		r = request_mem_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc");
 	if (!r) {
+#ifdef RTC_IRQ
+		rtc_has_irq = 0;
+#endif
 		printk(KERN_ERR "rtc: I/O resource %lx is not free.\n",
 		       (long)(RTC_PORT(0)));
 		return -EIO;
@@ -996,6 +1001,7 @@ no_irq:
 
 	if(request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED, "rtc", NULL)) {
 		/* Yeah right, seeing as irq 8 doesn't even hit the bus. */
+		rtc_has_irq = 0;
 		printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ);
 		if (RTC_IOMAPPED)
 			release_region(RTC_PORT(0), RTC_IO_EXTENT);
@@ -1012,6 +1018,7 @@ no_irq:
 	if (misc_register(&rtc_dev)) {
 #ifdef RTC_IRQ
 		free_irq(RTC_IRQ, NULL);
+		rtc_has_irq = 0;
 #endif
 		release_region(RTC_PORT(0), RTC_IO_EXTENT);
 		return -ENODEV;
@@ -1021,6 +1028,7 @@ no_irq:
 	if (!ent) {
 #ifdef RTC_IRQ
 		free_irq(RTC_IRQ, NULL);
+		rtc_has_irq = 0;
 #endif
 		release_region(RTC_PORT(0), RTC_IO_EXTENT);
 		misc_deregister(&rtc_dev);