[PATCH 2/3] mmc: Add mmc_vddrange_to_ocrmask() helper function

[Pierre Ossman]

On Thu, 30 Oct 2008 22:56:32 +0300
Anton Vorontsov <avorontsov at ru.mvista.com> wrote:

> +/**
> + * mmc_vddrange_to_ocrmask - Convert a voltage range to the OCR mask
> + * @vdd_min:	minimum voltage value (mV)
> + * @vdd_max:	maximum voltage value (mV)
> + * @mask:	pointer to the mask
> + *

Why the pointer? Why not let the caller handle the aggregation? That
would be a lot safer.

> +	/* fill the mask, from max bit to min bit */
> +	while (vdd_max >= vdd_min)
> +		*mask |= 1 << vdd_max--;
> +	return 0;

Many cards get a bit uppity with a single bit set. If possible, try to
make this function set two bits when the voltage is right on the
boundary (e.g. 3.3V).

Rgds
-- 
     -- Pierre Ossman

  Linux kernel, MMC maintainer        http://www.kernel.org
  rdesktop, core developer          http://www.rdesktop.org

  WARNING: This correspondence is being monitored by the
  Swedish government. Make sure your server uses encryption
  for SMTP traffic and consider using PGP for end-to-end
  encryption.