rtc-rs5c313.c: add error handling to avoid hardware hangup
Add error processing. Hanging up by an infinite loop is evaded.
Signed-off-by: kogiidena <kogiidena@eggplant.ddo.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-rs5c313.c b/drivers/rtc/rtc-rs5c313.c
index f964d1d..66eb133 100644
--- a/drivers/rtc/rtc-rs5c313.c
+++ b/drivers/rtc/rtc-rs5c313.c
@@ -212,7 +212,9 @@
static int rs5c313_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
int data;
+ int cnt;
+ cnt = 0;
while (1) {
RS5C313_CEENABLE; /* CE:H */
@@ -225,6 +227,10 @@
RS5C313_CEDISABLE;
ndelay(700); /* CE:L */
+ if (cnt++ > 100) {
+ dev_err(dev, "%s: timeout error\n", __FUNCTION__);
+ return -EIO;
+ }
}
data = rs5c313_read_reg(RS5C313_ADDR_SEC);
@@ -266,7 +272,9 @@
static int rs5c313_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
int data;
+ int cnt;
+ cnt = 0;
/* busy check. */
while (1) {
RS5C313_CEENABLE; /* CE:H */
@@ -279,6 +287,11 @@
RS5C313_MISCOP;
RS5C313_CEDISABLE;
ndelay(700); /* CE:L */
+
+ if (cnt++ > 100) {
+ dev_err(dev, "%s: timeout error\n", __FUNCTION__);
+ return -EIO;
+ }
}
data = BIN2BCD(tm->tm_sec);
@@ -317,6 +330,7 @@
static void rs5c313_check_xstp_bit(void)
{
struct rtc_time tm;
+ int cnt;
RS5C313_CEENABLE; /* CE:H */
if (rs5c313_read_cntreg() & RS5C313_CNTREG_WTEN_XSTP) {
@@ -326,8 +340,11 @@
rs5c313_write_cntreg(0x07);
/* busy check. */
- while (rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY)
+ for (cnt = 0; cnt < 100; cnt++) {
+ if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
+ break;
RS5C313_MISCOP;
+ }
memset(&tm, 0, sizeof(struct rtc_time));
tm.tm_mday = 1;