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authorLinus Torvalds <torvalds@linux-foundation.org>2018-10-29 14:44:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-29 14:44:03 -0700
commit57dbde63f2888af1be5111d369d124f4e659c0f8 (patch)
tree52b8e66f1f45f7076c2f65da56e78b0830efcfc6 /drivers/misc
parent134bf98c5596605af90f104716ef912e8f7eb56b (diff)
parent84de6e96e036dcfb18dded04a506b1dd72ba0e5b (diff)
downloadlinux-57dbde63f2888af1be5111d369d124f4e659c0f8.tar.bz2
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pca954x: simplify code to reach the adapter i2c: core: remove level of indentation in i2c_transfer i2c: core: remove outdated DEBUG output i2c: zx2967: use core to detect 'no zero length' quirk i2c: tegra: use core to detect 'no zero length' quirk i2c: qup: use core to detect 'no zero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 ...
Diffstat (limited to 'drivers/misc')
-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;
}