On Sat, Jan 25, 2014 at 06:14:45PM +0100, Jean-Francois Moine wrote:
> This patch adds more error checking inn I2C I/O functions.
> In case of I/O error, this permits to avoid writing in bad controller
> pages, a bad chipset detection or looping when getting the EDID.
I've just looked at this again, and spotted something:
> -static uint8_t
> +static int
> reg_read(struct tda998x_priv *priv, uint16_t reg)
> {
> uint8_t val = 0;
> - reg_read_range(priv, reg, &val, sizeof(val));
> + int ret;
> +
> + ret = reg_read_range(priv, reg, &val, sizeof(val));
> + if (ret < 0)
> + return ret;
So yes, this can return negative numbers.
> @@ -1158,8 +1184,11 @@ tda998x_encoder_init(struct i2c_client *client,
> tda998x_reset(priv);
>
> /* read version: */
> - priv->rev = reg_read(priv, REG_VERSION_LSB) |
> - reg_read(priv, REG_VERSION_MSB) << 8;
> + ret = reg_read(priv, REG_VERSION_LSB) |
> + (reg_read(priv, REG_VERSION_MSB) << 8);
> + if (ret < 0)
> + goto fail;
> + priv->rev = ret;
Two issues here:
1. The additional parens are /really/ not required.
2. What if reg_read(priv, REG_VERSION_MSB) returns a negative number?
If we're going to the extent of attempting to make the read/write
functions return errors, we should at least handle errors generated
by them properly, otherwise it's pointless making them return errors.
ret = reg_read(priv, REG_VERSION_LSB);
if (ret < 0)
goto fail;
priv->rev = ret;
ret = reg_read(priv, REG_VERSION_MSB);
if (ret < 0)
goto fail;
priv->rev |= ret << 8;
If you want it to look slightly nicer:
int rev_lo, rev_hi;
rev_lo = reg_read(priv, REG_VERSION_LSB);
rev_hi = reg_read(priv, REG_VERSION_MSB);
if (rev_lo < 0 || rev_hi < 0) {
ret = rev_lo < 0 ? rev_lo : rev_hi;
goto fail;
}
priv->rev = rev_lo | rev_hi << 8;
I'm happy to commit such a change after this patch to clean it up, or if
you want to regenerate your patch 2 and post /just/ that incorporating
this change.
--
FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation
in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad.
Estimate before purchase was "up to 13.2Mbit".
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