On 10/09/2020 16:35, Bartosz Golaszewski wrote: > On Thu, Sep 10, 2020 at 3:43 PM Jon Hunter <jonathanh@xxxxxxxxxx> wrote: >> >> The AT24 EEPROM driver does not initialise the 'id' field of the >> nvmem_config structure and because the entire structure is not >> initialised, it ends up with a random value. This causes the NVMEM >> driver to append the device 'devid' value to name of the NVMEM >> device. Although this is not a problem per-se, for I2C devices such as >> the AT24, that already have a device unique name, there does not seem >> much value in appending an additional 0 to the I2C name. For example, >> appending a 0 to an I2C device name such as 1-0050 does not seem >> necessary and maybe even a bit confusing. Therefore, fix this by >> setting the NVMEM config.id to NVMEM_DEVID_NONE for AT24 EEPROMs. >> >> Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx> >> --- >> drivers/misc/eeprom/at24.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c >> index e9df1ca251df..3f7a3bb6a36c 100644 >> --- a/drivers/misc/eeprom/at24.c >> +++ b/drivers/misc/eeprom/at24.c >> @@ -715,6 +715,7 @@ static int at24_probe(struct i2c_client *client) >> >> nvmem_config.name = dev_name(dev); >> nvmem_config.dev = dev; >> + nvmem_config.id = NVMEM_DEVID_NONE; >> nvmem_config.read_only = !writable; >> nvmem_config.root_only = !(flags & AT24_FLAG_IRUGO); >> nvmem_config.owner = THIS_MODULE; >> -- >> 2.25.1 >> > > This patch is correct and thanks for catching it. I vaguely recall > wondering at some point why the appended 0 in the nvmem name for at24. > Unfortunately this change would affect how the device is visible in > user-space in /sys/bus/nvmem/devices/ and this could break existing > users. Also: there are many in-kernel users that would need to be > updated. I'm afraid we'll need some sort of backward compatibility. Thanks, yes that is a problem. I guess for now we could explicitly init to NVMEM_DEVID_AUTO or maybe just 0 so that it defaults to the same path in the NVMEM driver. However, I am not sure how we can make allow some devices to use NVMEM_DEVID_NONE and others use something else. This is not really something that we can describe in DT because it has nothing to do with h/w. Cheers Jon -- nvpublic
