Re: [PATCH mt76 5/6] wifi: mt76: mt7996: fix the temporary buffer for calibration-free data

[Lorenzo Bianconi <lorenzo@kernel.org>]

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> From: StanleyYP Wang <StanleyYP.Wang@mediatek.com>
> 
> Move the declaration of buf[] outside the for loop.
> 
> Fixes: 224c7c2be578 ("wifi: mt76: mt7996: apply calibration-free data from OTP")
> Signed-off-by: StanleyYP Wang <StanleyYP.Wang@mediatek.com>
> Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
> ---
>  drivers/net/wireless/mediatek/mt76/mt7996/mcu.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
> index 2a9c59d15894..4c733f51a03e 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
> @@ -4104,6 +4104,7 @@ mt7996_mcu_get_cal_free_data(struct mt7996_dev *dev)
>  	}
>  
>  	for (band = 0; band < __MT_MAX_BAND; band++) {
> +		u8 buf[MT7996_EEPROM_BLOCK_SIZE];

why are you moving buf here? It is only used in the inner block.

>  		const struct cal_free_data *cal;
>  		u16 prev_block_idx = -1;
>  		u16 adie_base;
> @@ -4126,13 +4127,13 @@ mt7996_mcu_get_cal_free_data(struct mt7996_dev *dev)
>  			u16 eep_offset = cal[i].eep_offs;
>  			u16 block_idx = adie_offset / MT7996_EEPROM_BLOCK_SIZE;
>  			u16 offset = adie_offset % MT7996_EEPROM_BLOCK_SIZE;
> -			u8 buf[MT7996_EEPROM_BLOCK_SIZE];

I think we should always define and initialize buf array here, otherwise we
could use it with uninitialized values. Something like:

			u8 buf[MT7996_EEPROM_BLOCK_SIZE] = {};

Regards,
Lorenzo

>  
>  			if (is_mt7996(&dev->mt76) && band == MT_BAND1 &&
>  			    dev->var.type == MT7996_VAR_TYPE_444)
>  				eep_offset -= MT_EE_7977BN_OFFSET;
>  
>  			if (prev_block_idx != block_idx) {
> +				memset(buf, 0, sizeof(buf));
>  				ret = mt7996_mcu_get_eeprom(dev, adie_offset, buf,
>  							    MT7996_EEPROM_BLOCK_SIZE,
>  							    EEPROM_MODE_EFUSE);
> -- 
> 2.51.0
> 

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