Merge branch 'i2c/for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "I2C has not so much stuff this time. Mostly driver enablement for new
  SoCs, some driver bugfixes, and some cleanups"

* 'i2c/for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (35 commits)
  MAINTAINERS: add maintainer for Renesas RIIC driver
  i2c: sh_mobile: Remove dummy runtime PM callbacks
  i2c: uniphier-f: fix race condition when IRQ is cleared
  i2c: uniphier-f: fix occasional timeout error
  i2c: uniphier-f: make driver robust against concurrency
  i2c: i2c-qcom-geni: Simplify irq handler
  i2c: i2c-qcom-geni: Simplify tx/rx functions
  i2c: designware: Set IRQF_NO_SUSPEND flag for all BYT and CHT controllers
  i2c: mux: mlxcpld: simplify code to reach the adapter
  i2c: mux: ltc4306: simplify code to reach the adapter
  i2c: mux: pca954x: simplify code to reach the adapter
  i2c: core: remove level of indentation in i2c_transfer
  i2c: core: remove outdated DEBUG output
  i2c: zx2967: use core to detect 'no zero length' quirk
  i2c: tegra: use core to detect 'no zero length' quirk
  i2c: qup: use core to detect 'no zero length' quirk
  i2c: omap: use core to detect 'no zero length' quirk
  i2c: Convert to using %pOFn instead of device_node.name
  i2c: brcmstb: Allow enabling the driver on DSL SoCs
  eeprom: at24: fix unexpected timeout under high load
  ...

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;
 }