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-rw-r--r--drivers/misc/eeprom/at24.c43
1 files changed, 22 insertions, 21 deletions
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 7e50e1d6f58c..636ed7149793 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -106,23 +106,6 @@ static unsigned int at24_write_timeout = 25;
module_param_named(write_timeout, at24_write_timeout, uint, 0);
MODULE_PARM_DESC(at24_write_timeout, "Time (in ms) to try writes (default 25)");
-/*
- * Both reads and writes fail if the previous write didn't complete yet. This
- * macro loops a few times waiting at least long enough for one entire page
- * write to work while making sure that at least one iteration is run before
- * checking the break condition.
- *
- * It takes two parameters: a variable in which the future timeout in jiffies
- * will be stored and a temporary variable holding the time of the last
- * iteration of processing the request. Both should be unsigned integers
- * holding at least 32 bits.
- */
-#define at24_loop_until_timeout(tout, op_time) \
- for (tout = jiffies + msecs_to_jiffies(at24_write_timeout), \
- op_time = 0; \
- op_time ? time_before(op_time, tout) : true; \
- usleep_range(1000, 1500), op_time = jiffies)
-
struct at24_chip_data {
/*
* these fields mirror their equivalents in
@@ -308,13 +291,22 @@ static ssize_t at24_regmap_read(struct at24_data *at24, char *buf,
/* adjust offset for mac and serial read ops */
offset += at24->offset_adj;
- at24_loop_until_timeout(timeout, read_time) {
+ timeout = jiffies + msecs_to_jiffies(at24_write_timeout);
+ do {
+ /*
+ * The timestamp shall be taken before the actual operation
+ * to avoid a premature timeout in case of high CPU load.
+ */
+ read_time = jiffies;
+
ret = regmap_bulk_read(regmap, offset, buf, count);
dev_dbg(&client->dev, "read %zu@%d --> %d (%ld)\n",
count, offset, ret, jiffies);
if (!ret)
return count;
- }
+
+ usleep_range(1000, 1500);
+ } while (time_before(read_time, timeout));
return -ETIMEDOUT;
}
@@ -358,14 +350,23 @@ static ssize_t at24_regmap_write(struct at24_data *at24, const char *buf,
regmap = at24_client->regmap;
client = at24_client->client;
count = at24_adjust_write_count(at24, offset, count);
+ timeout = jiffies + msecs_to_jiffies(at24_write_timeout);
+
+ do {
+ /*
+ * The timestamp shall be taken before the actual operation
+ * to avoid a premature timeout in case of high CPU load.
+ */
+ write_time = jiffies;
- at24_loop_until_timeout(timeout, write_time) {
ret = regmap_bulk_write(regmap, offset, buf, count);
dev_dbg(&client->dev, "write %zu@%d --> %d (%ld)\n",
count, offset, ret, jiffies);
if (!ret)
return count;
- }
+
+ usleep_range(1000, 1500);
+ } while (time_before(write_time, timeout));
return -ETIMEDOUT;
}
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