Re: [PATCH 04/13] eeprom: at24: make locking more fine-grained (fwd)

From: Julia Lawall
Date: Thu Mar 24 2016 - 12:30:27 EST

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If this is correct, it seems quite subtle.

julia

---------- Forwarded message ----------
Date: Fri, 25 Mar 2016 00:25:33 +0800
From: kbuild test robot <fengguang.wu@xxxxxxxxx>
To: kbuild@xxxxxx
Cc: Julia Lawall <julia.lawall@xxxxxxx>
Subject: Re: [PATCH 04/13] eeprom: at24: make locking more fine-grained

CC: kbuild-all@xxxxxx
In-Reply-To: <1458830767-23816-5-git-send-email-bgolaszewski@xxxxxxxxxxxx>
TO: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
CC: Wolfram Sang <wsa@xxxxxxxxxxxxx>, linux-i2c <linux-i2c@xxxxxxxxxxxxxxx>, LKML <linux-kernel@xxxxxxxxxxxxxxx>
CC: Andrew Lunn <andrew@xxxxxxx>, Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>

Hi Bartosz,

[auto build test WARNING on next-20160324]
[cannot apply to v4.5-rc7 v4.5-rc6 v4.5-rc5 v4.5]
[if your patch is applied to the wrong git tree, please drop us a note to help improving the system]

url: https://github.com/0day-ci/linux/commits/Bartosz-Golaszewski/eeprom-support-for-at24cs-and-at24mac/20160324-230008
:::::: branch date: 85 minutes ago
:::::: commit date: 85 minutes ago

>> drivers/misc/eeprom/at24.c:356:3-9: preceding lock on line 312

git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 9e24d3f64066d8452c1ab00486a5a4878a30b7b1
vim +356 drivers/misc/eeprom/at24.c

2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 306 if (!at24->use_smbus) {
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 307 int i = 0;
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 308
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 309 msg.addr = client->addr;
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 310 msg.flags = 0;
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 311
9e24d3f6 drivers/misc/eeprom/at24.c Bartosz Golaszewski 2016-03-24 @312 mutex_lock(&at24->wrbuf_lock);
9e24d3f6 drivers/misc/eeprom/at24.c Bartosz Golaszewski 2016-03-24 313
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 314 /* msg.buf is u8 and casts will mask the values */
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 315 msg.buf = at24->writebuf;
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 316 if (at24->chip.flags & AT24_FLAG_ADDR16)
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 317 msg.buf[i++] = offset >> 8;
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 318
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 319 msg.buf[i++] = offset;
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 320 memcpy(&msg.buf[i], buf, count);
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 321 msg.len = i + count;
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 322 }
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 323
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 324 /*
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 325 * Writes fail if the previous one didn't complete yet. We may
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 326 * loop a few times until this one succeeds, waiting at least
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 327 * long enough for one entire page write to work.
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 328 */
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 329 timeout = jiffies + msecs_to_jiffies(write_timeout);
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 330 do {
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 331 write_time = jiffies;
a839ce66 drivers/misc/eeprom/at24.c Christian Gmeiner 2014-10-09 332 if (at24->use_smbus_write) {
a839ce66 drivers/misc/eeprom/at24.c Christian Gmeiner 2014-10-09 333 switch (at24->use_smbus_write) {
a839ce66 drivers/misc/eeprom/at24.c Christian Gmeiner 2014-10-09 334 case I2C_SMBUS_I2C_BLOCK_DATA:
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 335 status = i2c_smbus_write_i2c_block_data(client,
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 336 offset, count, buf);
a839ce66 drivers/misc/eeprom/at24.c Christian Gmeiner 2014-10-09 337 break;
a839ce66 drivers/misc/eeprom/at24.c Christian Gmeiner 2014-10-09 338 case I2C_SMBUS_BYTE_DATA:
a839ce66 drivers/misc/eeprom/at24.c Christian Gmeiner 2014-10-09 339 status = i2c_smbus_write_byte_data(client,
a839ce66 drivers/misc/eeprom/at24.c Christian Gmeiner 2014-10-09 340 offset, buf[0]);
a839ce66 drivers/misc/eeprom/at24.c Christian Gmeiner 2014-10-09 341 break;
a839ce66 drivers/misc/eeprom/at24.c Christian Gmeiner 2014-10-09 342 }
a839ce66 drivers/misc/eeprom/at24.c Christian Gmeiner 2014-10-09 343
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 344 if (status == 0)
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 345 status = count;
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 346 } else {
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 347 status = i2c_transfer(client->adapter, &msg, 1);
9e24d3f6 drivers/misc/eeprom/at24.c Bartosz Golaszewski 2016-03-24 348 mutex_unlock(&at24->wrbuf_lock);
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 349 if (status == 1)
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 350 status = count;
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 351 }
2ce5b34f drivers/i2c/chips/at24.c David Brownell 2008-08-10 352 dev_dbg(&client->dev, "write %zu@%d --> %zd (%ld)\n",
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 353 count, offset, status, jiffies);
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 354
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 355 if (status == count)
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 @356 return count;
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 357
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 358 /* REVISIT: at HZ=100, this is sloooow */
2b7a5056 drivers/i2c/chips/at24.c Wolfram Sang 2008-07-14 359 msleep(1);

:::::: The code at line 356 was first introduced by commit
:::::: 2b7a5056a0a7ff17d5d2004c29c852a92a6bd632 i2c: New-style EEPROM driver using device IDs

:::::: TO: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
:::::: CC: Jean Delvare <khali@xxxxxxxxxxxxxxxx>

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Previous message: Russell King - ARM Linux: "Re: [PATCH] mmc: dw_mmc: Wait for data transfer after response errors"
Next in thread: Bartosz Golaszewski: "Re: [PATCH 04/13] eeprom: at24: make locking more fine-grained (fwd)"
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