On Fri, Oct 11, 2024 at 02:31:00PM +0200, Javier Carrasco wrote: > On 11/10/2024 13:52, Yo-Jung (Leo) Lin wrote: > > clang found that the "offset" in bmp580_trigger_handler doesn't get > > initialized before access. Add proper initialization to this variable. > > > > Signed-off-by: Yo-Jung (Leo) Lin <0xff07@xxxxxxxxx> > > --- > > Change in v2: > > - Make value initialization immediate before its first use. > > - Link to v1: https://lore.kernel.org/all/20241011093752.30685-1-0xff07@xxxxxxxxx/ > > > > --- > > drivers/iio/pressure/bmp280-core.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c > > index f4df222ed0c3..682329f81886 100644 > > --- a/drivers/iio/pressure/bmp280-core.c > > +++ b/drivers/iio/pressure/bmp280-core.c > > @@ -2222,6 +2222,8 @@ static irqreturn_t bmp580_trigger_handler(int irq, void *p) > > goto out; > > } > > > > + offset = 0; > > + > > /* Pressure calculations */ > > memcpy(&data->sensor_data[offset], &data->buf[3], 3); > > > > That was a quick reply. I would recommend you to wait a little bit while > the first version is under discussion. > > I still see the offset thing a bit weird. data->sensor_data uses an > offset to avoid hard-coded numbers, but for data->buf we do exactly > that, in the very same lines. > > Setting offset to 0 to access the first element i.e. no offset required, > and then adding the actual offset sizeof(s32), which could even be a > const if the first access was to sensor_data[0], looks to verbose. > > These things are of course not critical, and the proposed fix is > definitely ok, but I am missing some consistency here. Hi everyone! So if you check also the conversations that we had here [1] and in the previous versions, indeed the idea behind the offset is to use it as an self-explanatory index to a char buffer that holds in fact s32 variables. The data->buf here holds the values that have just been read from the sensor. If you check on the channel specification of this sensor, you will see ".realbits = 24" in both values that the sensor returns so hence the value 3. I am not sure if it makes sense to use a macro here for each one of the 3's that are going to be used only one time each and in order to be more "consistent". But I might have a wrong view on this one so feel free to correct me! For the initialization of the offset indeed, it was already mentioned here [2] this morning, but on a different patch!!! I couldn't get this error though with gcc... Cheers, Vasilis [1]: https://lore.kernel.org/all/20240930202353.38203-3-vassilisamir@xxxxxxxxx/ [2]: https://lore.kernel.org/linux-iio/202410111221.YIeXHxOv-lkp@xxxxxxxxx/
