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|
Retry up to 200 ms when reading or writing keys.
From: Nicolas Boichat <nicolas@boichat.ch>
---
drivers/hwmon/applesmc.c | 69 +++++++++++++++++++++++++++++++---------------
1 files changed, 47 insertions(+), 22 deletions(-)
diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
index c0dd9b1..3b09cdb 100644
--- a/drivers/hwmon/applesmc.c
+++ b/drivers/hwmon/applesmc.c
@@ -112,6 +112,9 @@ static const char* fan_speed_keys[] = {
#define INIT_TIMEOUT_MSECS 5000 /* wait up to 5s for device init ... */
#define INIT_WAIT_MSECS 50 /* ... in 50ms increments */
+#define ACCESS_TIMEOUT_MSECS 500 /* wait up to 500ms when accessing a key */
+#define ACCESS_WAIT_MSECS 5 /* ... in 5ms increments */
+
#define APPLESMC_POLL_INTERVAL 50 /* msecs */
#define APPLESMC_INPUT_FUZZ 4 /* input event threshold */
#define APPLESMC_INPUT_FLAT 4
@@ -186,12 +189,13 @@ static int __wait_status(u8 val)
/*
* applesmc_read_key - reads len bytes from a given key, and put them in buffer.
+ * Tries up to ACCESS_WAIT_MSECS to read the value.
* Returns zero on success or a negative error on failure. Callers must
* hold applesmc_lock.
*/
static int applesmc_read_key(const char* key, u8* buffer, u8 len)
{
- int i;
+ int i, total, ret;
if (len > APPLESMC_MAX_DATA_LENGTH) {
printk(KERN_ERR "applesmc_read_key: cannot read more than "
@@ -199,33 +203,54 @@ static int applesmc_read_key(const char* key, u8* buffer, u8 len)
return -EINVAL;
}
- outb(APPLESMC_READ_CMD, APPLESMC_CMD_PORT);
- if (__wait_status(0x0c))
- return -EIO;
+ for (total = ACCESS_TIMEOUT_MSECS; total > 0;
+ total -= ACCESS_WAIT_MSECS) {
+ ret = 0;
+ outb(APPLESMC_READ_CMD, APPLESMC_CMD_PORT);
+ if (__wait_status(0x0c)) {
+ ret = -EIO;
+ goto wait_fail;
+ }
- for (i = 0; i < 4; i++) {
- outb(key[i], APPLESMC_DATA_PORT);
- if (__wait_status(0x04))
- return -EIO;
- }
- if (debug)
- printk(KERN_DEBUG "<%s", key);
+ for (i = 0; i < 4; i++) {
+ outb(key[i], APPLESMC_DATA_PORT);
+ if (__wait_status(0x04)) {
+ ret = -EIO;
+ goto wait_fail;
+ }
+ }
+ if (debug)
+ printk(KERN_DEBUG "<%s", key);
- outb(len, APPLESMC_DATA_PORT);
- if (debug)
- printk(KERN_DEBUG ">%x", len);
+ outb(len, APPLESMC_DATA_PORT);
+ if (debug)
+ printk(KERN_DEBUG ">%x", len);
- for (i = 0; i < len; i++) {
- if (__wait_status(0x05))
- return -EIO;
- buffer[i] = inb(APPLESMC_DATA_PORT);
+ for (i = 0; i < len; i++) {
+ if (__wait_status(0x05)) {
+ ret = -EIO;
+ goto wait_fail;
+ }
+ buffer[i] = inb(APPLESMC_DATA_PORT);
+ if (debug)
+ printk(KERN_DEBUG "<%x", buffer[i]);
+ }
if (debug)
- printk(KERN_DEBUG "<%x", buffer[i]);
+ printk(KERN_DEBUG "\n");
+
+ break;
+
+wait_fail:
+ msleep(ACCESS_WAIT_MSECS);
+ continue;
}
- if (debug)
- printk(KERN_DEBUG "\n");
- return 0;
+ if (total != ACCESS_TIMEOUT_MSECS) {
+ printk(KERN_DEBUG "Read: Waited %d ms for the value\n",
+ ACCESS_TIMEOUT_MSECS-total);
+ }
+
+ return ret;
}
/*
|
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