Subject: Re: [PATCH net-next] r8169: remove not needed check in rtl_fw_write_firmware

From: Simon Horman <[email-masked]>
Date: Thu, 23 Nov 2023 14:54:07 +0000

On Thu, Nov 23, 2023 at 10:53:26AM +0100, Heiner Kallweit wrote:
> This check can never be true for a firmware file with a correct format.
> Existing checks in rtl_fw_data_ok() are sufficient, no problems with
> invalid firmware files are known.
> 
> Signed-off-by: Heiner Kallweit <[email-masked]>
> ---
>  drivers/net/ethernet/realtek/r8169_firmware.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/realtek/r8169_firmware.c b/drivers/net/ethernet/realtek/r8169_firmware.c
> index cbc6b846d..ed6e721b1 100644
> --- a/drivers/net/ethernet/realtek/r8169_firmware.c
> +++ b/drivers/net/ethernet/realtek/r8169_firmware.c
> @@ -151,9 +151,6 @@ void rtl_fw_write_firmware(struct rtl8169_private *tp, struct rtl_fw *rtl_fw)
>  		u32 regno = (action & 0x0fff0000) >> 16;
>  		enum rtl_fw_opcode opcode = action >> 28;
>  
> -		if (!action)
> -			break;
> -

Hi Heiner,

I could well be wrong, but this does seem to guard against the following case:

1. data = 0
2. regno = 0
3. opcode = 0 (PHY_READ)

Which does not seem to be checked in rtl_fw_data_ok().

It's unclear to me if there is any value in this guard.

>  		switch (opcode) {
>  		case PHY_READ:
>  			predata = fw_read(tp, regno);
> -- 
> 2.43.0
>