Re: [PATCH] iio: accel: adxl380: clamp FIFO sample count

["Shengzhuo Wei" <me@cherr.cc>]

在 2026-08-10 00:28，Jonathan Cameron 写道：
> > Fixes: df36de13677a ("iio: accel: add ADXL380 driver")
> 
> In my opinion at least, these are not fixes. In general we don't expect
> drivers to be hardened against broken hardware returning out of spec
> values.  I don't mind taking simple cases though that don't complicate
> the code much and if anything make it a little easier to follow,
> but I don't currently see any reason to mark them as a fix.
> 
> So drop that tag for v2.
> 

Hi Jonathan,

Thanks. Understood — I'll drop the Fixes tag and stop clamping. 

> This is papering over what we think is a hardware failure. Unless I am
> missing something the device is returning garbage, otherwise we are in
> range and this has no affect. We have no idea how much data there is
> if we get a value outside the expected range. 
> 
> As such I'd expect an error print and probably no attempt to carry
> on reading as we have no idea what happened.

For v2 I'll treat an out-of-range count as a hardware error, 
log it, and skip the read rather than carrying on:

    ret = adxl380_get_fifo_entries(st, &fifo_entries);
    if (ret)
            return IRQ_HANDLED;

    if (fifo_entries > ADXL380_FIFO_SAMPLES) {
            dev_err_ratelimited(st->dev,
                                "invalid FIFO entry count %u (max %lu)\n",
                                fifo_entries, ADXL380_FIFO_SAMPLES);
            return IRQ_HANDLED;
    }

    fifo_entries = rounddown(fifo_entries, st->fifo_set_size);
    ret = regmap_noinc_read(st->regmap, ADXL380_FIFO_DATA, &st->fifo_buf,
                            sizeof(*st->fifo_buf) * fifo_entries);

Same for adxl367 (push_fifo_data: dev_err_ratelimited and return true
without reading the FIFO).

I'll send the two as a single series with a cover letter, no Fixes tags.

Let me know if this looks OK to you, or if you'd change anything, and
I'll send the v2 series.

Best regards,
Shengzhuo Wei