On Fri, Mar 29, 2019 at 12:02:44AM +0000, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> Currently the lower 8 bits of ret are being masked and left
> shifted by 8 bits always leaving a result of zero. The mask
> appears to be incorrect and should probably be 0xff00 instead
> of 0xff. Fix this. (Note: not tested).
>
> Fixes: 16feab644fd1 ("staging: rtl8192u: check return value eprom_read")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
> drivers/staging/rtl8192u/r8192U_core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/staging/rtl8192u/r8192U_core.c b/drivers/staging/rtl8192u/r8192U_core.c
> index f1eaab337dca..a173884d31c8 100644
> --- a/drivers/staging/rtl8192u/r8192U_core.c
> +++ b/drivers/staging/rtl8192u/r8192U_core.c
> @@ -2454,7 +2454,7 @@ static int rtl8192_read_eeprom_info(struct net_device *dev)
> ret = eprom_read(dev, (EEPROM_TX_PW_INDEX_CCK >> 1));
> if (ret < 0)
> return ret;
> - priv->EEPROMTxPowerLevelCCK = ((u16)ret & 0xff) >> 8;
> + priv->EEPROMTxPowerLevelCCK = ((u16)ret & 0xff00) >> 8;
I'd say there is a 80-90% chance your fix is correct...
This only affects an older rev of the eeprom I think. I believe what
happens in the current code is that we set EEPROMTxPowerLevelCCK to
zero. Then we subtract:
priv->TxPowerLevelCCK[i] = priv->EEPROMTxPowerLevelOFDM24G[0] + (priv->EEPROMTxPowerLevelCCK - priv->EEPROMTxPowerLevelOFDM24G[1]);
Possibly leading to a high u8 value, then in phy_set_rf8256_cck_tx_power()
it gets capped at 0x24...
regards,
dan carpenter
