2017-12-02 15:48 GMT+01:00 Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>:
> Hi,
>
> On Fri, Dec 01, 2017 at 01:37:12PM -0500, Sven Van Asbroeck wrote:
>> From: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
>>
>> The at24 driver creates dummy I2C devices to access offsets in the chip
>> that are outside the area supported using a single I2C address. It is not
>> meaningful to use runtime PM to such devices; the system firmware (ACPI)
>> does not know about these devices nor runtime PM was enabled for them.
>> Always use the real device instead of the dummy ones.
>>
>> Fixes: 98e8201039af ("eeprom: at24: enable runtime pm support")
>> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
>> Tested-by: Sven Van Asbroeck on a 24AA16/24LC16B <svendev@xxxxxxxx>
>> [Bartosz: rebased on top of previous fixes for 4.15, tweaked the
>> commit message]
>> [Sven: fixed Bartosz's rebase]
>> Signed-off-by: Sven Van Asbroeck <svendev@xxxxxxxx>
>> Signed-off-by: Bartosz Golaszewski <brgl@xxxxxxxx>
>
> I presume this is the final one. Yeah, the client variable was effectively
> unused in the earlier version. Seems good to me.
>
>> ---
>> drivers/misc/eeprom/at24.c | 24 ++++++++++--------------
>> 1 file changed, 10 insertions(+), 14 deletions(-)
>>
>> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
>> index 305a7a4..20b4f26 100644
>> --- a/drivers/misc/eeprom/at24.c
>> +++ b/drivers/misc/eeprom/at24.c
>> @@ -562,7 +562,7 @@ static ssize_t at24_eeprom_write_i2c(struct at24_data *at24, const char *buf,
>> static int at24_read(void *priv, unsigned int off, void *val, size_t count)
>> {
>> struct at24_data *at24 = priv;
>> - struct i2c_client *client;
>> + struct device *dev = &at24->client[0]->dev;
>> char *buf = val;
>> int ret;
>>
>> @@ -572,11 +572,9 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count)
>> if (off + count > at24->chip.byte_len)
>> return -EINVAL;
>>
>> - client = at24_translate_offset(at24, &off);
>> -
>> - ret = pm_runtime_get_sync(&client->dev);
>> + ret = pm_runtime_get_sync(dev);
>> if (ret < 0) {
>> - pm_runtime_put_noidle(&client->dev);
>> + pm_runtime_put_noidle(dev);
>> return ret;
>> }
>>
>> @@ -592,7 +590,7 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count)
>> status = at24->read_func(at24, buf, off, count);
>> if (status < 0) {
>> mutex_unlock(&at24->lock);
>> - pm_runtime_put(&client->dev);
>> + pm_runtime_put(dev);
>> return status;
>> }
>> buf += status;
>> @@ -602,7 +600,7 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count)
>>
>> mutex_unlock(&at24->lock);
>>
>> - pm_runtime_put(&client->dev);
>> + pm_runtime_put(dev);
>>
>> return 0;
>> }
>> @@ -610,7 +608,7 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count)
>> static int at24_write(void *priv, unsigned int off, void *val, size_t count)
>> {
>> struct at24_data *at24 = priv;
>> - struct i2c_client *client;
>> + struct device *dev = &at24->client[0]->dev;
>> char *buf = val;
>> int ret;
>>
>> @@ -620,11 +618,9 @@ static int at24_write(void *priv, unsigned int off, void *val, size_t count)
>> if (off + count > at24->chip.byte_len)
>> return -EINVAL;
>>
>> - client = at24_translate_offset(at24, &off);
>> -
>> - ret = pm_runtime_get_sync(&client->dev);
>> + ret = pm_runtime_get_sync(dev);
>> if (ret < 0) {
>> - pm_runtime_put_noidle(&client->dev);
>> + pm_runtime_put_noidle(dev);
>> return ret;
>> }
>>
>> @@ -640,7 +636,7 @@ static int at24_write(void *priv, unsigned int off, void *val, size_t count)
>> status = at24->write_func(at24, buf, off, count);
>> if (status < 0) {
>> mutex_unlock(&at24->lock);
>> - pm_runtime_put(&client->dev);
>> + pm_runtime_put(dev);
>> return status;
>> }
>> buf += status;
>> @@ -650,7 +646,7 @@ static int at24_write(void *priv, unsigned int off, void *val, size_t count)
>>
>> mutex_unlock(&at24->lock);
>>
>> - pm_runtime_put(&client->dev);
>> + pm_runtime_put(dev);
>>
>> return 0;
>> }
>> --
>> 1.9.1
>>
>
> --
> Sakari Ailus
> sakari.ailus@xxxxxxxxxxxxxxx
Sven informed me in private that the bug was actually triggered by a
HW issue on the board he was using and not the code itself, but I
believe this fix makes sense nevertheless, so I queued it for
4.15-rc3. Thanks!
Bartosz
