drivers/mfd/tps65910.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)
In tps65910_i2c_probe(), a dummy I2C transfer is performed to work
around silicon erratum SWCZ010. However, the return value of
i2c_master_send() is not checked.
If this dummy transfer fails, the driver continues execution without
detecting the error. This may lead to subsequent I2C operations also
failing, but the driver would incorrectly report success.
Add proper return value checking for the dummy I2C transfer. If the
transfer fails, log the error and return an appropriate error code
to the caller.
Signed-off-by: Wenyuan Li <2063309626@qq.com>
---
v2:
- Use dev_err_probe() for error handling
- Replace ternary operator with if/else
- Add TPS65910_DUMMY_XFER_LEN macro
---
drivers/mfd/tps65910.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/mfd/tps65910.c b/drivers/mfd/tps65910.c
index 6a7b7a697fb7..31e4726118b3 100644
--- a/drivers/mfd/tps65910.c
+++ b/drivers/mfd/tps65910.c
@@ -21,6 +21,9 @@
#include <linux/of.h>
#include <linux/property.h>
+/* Dummy I2C transfer length for SWCZ010 workaround */
+#define TPS65910_DUMMY_XFER_LEN 1
+
static const struct resource rtc_resources[] = {
{
.start = TPS65910_IRQ_RTC_ALARM,
@@ -472,7 +475,18 @@ static int tps65910_i2c_probe(struct i2c_client *i2c)
* first I2C transfer. So issue a dummy transfer before the first
* real transfer.
*/
- i2c_master_send(i2c, "", 1);
+ ret = i2c_master_send(i2c, "", TPS65910_DUMMY_XFER_LEN);
+ if (ret != TPS65910_DUMMY_XFER_LEN) {
+ int err;
+
+ if (ret < 0)
+ err = ret;
+ else
+ err = -EIO;
+
+ return dev_err_probe(&i2c->dev, err, "dummy transfer failed\n");
+ }
+
tps65910->regmap = devm_regmap_init_i2c(i2c, &tps65910_regmap_config);
if (IS_ERR(tps65910->regmap)) {
ret = PTR_ERR(tps65910->regmap);
--
2.43.0Hi Wenyuan,
kernel test robot noticed the following build warnings:
[auto build test WARNING on lee-leds/for-leds-next]
[also build test WARNING on lee-mfd/for-mfd-next lee-mfd/for-mfd-fixes linus/master v7.0-rc6 next-20260330]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Wenyuan-Li/mfd-tps65910-add-error-handling-for-dummy-I2C-transfer-in-probe/20260331-203820
base: https://git.kernel.org/pub/scm/linux/kernel/git/lee/leds.git for-leds-next
patch link: https://lore.kernel.org/r/tencent_74C5C53384C579056ED161B70122D16ACF06%40qq.com
patch subject: [PATCH v2] mfd: tps65910: add error handling for dummy I2C transfer in probe
config: arm64-randconfig-r072-20260401 (https://download.01.org/0day-ci/archive/20260401/202604011034.5GOHWfcw-lkp@intel.com/config)
compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 2cd67b8b69f78e3f95918204320c3075a74ba16c)
smatch: v0.5.0-9004-gb810ac53
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202604011034.5GOHWfcw-lkp@intel.com/
smatch warnings:
drivers/mfd/tps65910.c:487 tps65910_i2c_probe() warn: inconsistent indenting
vim +487 drivers/mfd/tps65910.c
439
440 static int tps65910_i2c_probe(struct i2c_client *i2c)
441 {
442 const struct i2c_device_id *id = i2c_client_get_device_id(i2c);
443 struct tps65910 *tps65910;
444 struct tps65910_board *pmic_plat_data;
445 struct tps65910_board *of_pmic_plat_data = NULL;
446 struct tps65910_platform_data *init_data;
447 unsigned long chip_id = id->driver_data;
448 int ret;
449
450 pmic_plat_data = dev_get_platdata(&i2c->dev);
451
452 if (!pmic_plat_data && i2c->dev.of_node) {
453 pmic_plat_data = tps65910_parse_dt(i2c, &chip_id);
454 of_pmic_plat_data = pmic_plat_data;
455 }
456
457 if (!pmic_plat_data)
458 return -EINVAL;
459
460 init_data = devm_kzalloc(&i2c->dev, sizeof(*init_data), GFP_KERNEL);
461 if (init_data == NULL)
462 return -ENOMEM;
463
464 tps65910 = devm_kzalloc(&i2c->dev, sizeof(*tps65910), GFP_KERNEL);
465 if (tps65910 == NULL)
466 return -ENOMEM;
467
468 tps65910->of_plat_data = of_pmic_plat_data;
469 i2c_set_clientdata(i2c, tps65910);
470 tps65910->dev = &i2c->dev;
471 tps65910->i2c_client = i2c;
472 tps65910->id = chip_id;
473
474 /* Work around silicon erratum SWCZ010: the tps65910 may miss the
475 * first I2C transfer. So issue a dummy transfer before the first
476 * real transfer.
477 */
478 ret = i2c_master_send(i2c, "", TPS65910_DUMMY_XFER_LEN);
479 if (ret != TPS65910_DUMMY_XFER_LEN) {
480 int err;
481
482 if (ret < 0)
483 err = ret;
484 else
485 err = -EIO;
486
> 487 return dev_err_probe(&i2c->dev, err, "dummy transfer failed\n");
488 }
489
490 tps65910->regmap = devm_regmap_init_i2c(i2c, &tps65910_regmap_config);
491 if (IS_ERR(tps65910->regmap)) {
492 ret = PTR_ERR(tps65910->regmap);
493 dev_err(&i2c->dev, "regmap initialization failed: %d\n", ret);
494 return ret;
495 }
496
497 init_data->irq = pmic_plat_data->irq;
498 init_data->irq_base = pmic_plat_data->irq_base;
499
500 tps65910_irq_init(tps65910, init_data->irq, init_data);
501 tps65910_ck32k_init(tps65910, pmic_plat_data);
502 tps65910_sleepinit(tps65910, pmic_plat_data);
503
504 if (pmic_plat_data->pm_off && !pm_power_off) {
505 /*
506 * The PWR_OFF bit needs to be set separately, before
507 * transitioning to the OFF state. It enables the "sequential"
508 * power-off mode on TPS65911, it's a NO-OP on TPS65910.
509 */
510 ret = regmap_set_bits(tps65910->regmap, TPS65910_DEVCTRL,
511 DEVCTRL_PWR_OFF_MASK);
512 if (ret) {
513 dev_err(&i2c->dev, "failed to set power-off mode: %d\n",
514 ret);
515 return ret;
516 }
517
518 tps65910_i2c_client = i2c;
519 pm_power_off = tps65910_power_off;
520 }
521
522 ret = devm_mfd_add_devices(tps65910->dev, -1,
523 tps65910s, ARRAY_SIZE(tps65910s),
524 NULL, 0,
525 regmap_irq_get_domain(tps65910->irq_data));
526 if (ret < 0) {
527 dev_err(&i2c->dev, "mfd_add_devices failed: %d\n", ret);
528 return ret;
529 }
530
531 return ret;
532 }
533
--
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