Messages in this thread | | | Date | Thu, 24 May 2012 13:14:52 +0100 | From | Mark Brown <> | Subject | Re: mc13xxx-core: kernel hangs after 'regmap_read' |
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On Thu, May 24, 2012 at 09:22:29PM +1000, Marc Reilly wrote:
> > > map->reg_shift = config->pad_bits % 8; > > > map->format.buf_size = (config->reg_bits > > > > > > + config->val_bits > > > > > > + map->reg_shift) / 8;
> > Yes, that's been missed in the addition of padding. We should also be > > using DIV_ROUND_UP() which we aren't at the minute.
> That would break, in _regmap_read_raw():
> ret = map->bus->read(map->bus_context, map->work_buf, > map->format.reg_bytes + map->format.pad_bytes, > val, val_len);
> If pad_bytes was 1 here, then the register size would end up being 2 bytes.
The above is about buf_size... pad_bytes isn't in the quoted text which is the issue.
> The way I understood the pad_bytes field was it was the number of _complete_ > padding bytes (ie, full 8 bits) between the register address and value. Any > remainder of padding bits is incorporated into the register and shifted by > shift bits.
Yes.
> > We could also do > > reg_bytes + pad_bytes + val_bytes which should cover everything I think?
> If we want to cover everything, we could do reg_bytes + pad_bytes + val_bytes > + 3 ... :) (I'm not seriously suggesting that).
Yes, but the above should be the total that goes onto the wire.
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