Re: [PATCH] net/r8169: Update the new parser for the new firmware

[Francois Romieu <romieu@fr.zoreil.com>]

Hayes Wang <hayeswang@realtek.com> :
> Update the parser for the new firmware which is embedded some information.
> The paser cannot be used for the old firmware. It is only for the new type one.

> 
> Signed-off-by: Hayes Wang <hayeswang@realtek.com>
> ---
>  drivers/net/r8169.c |   59 ++++++++++++++++++++++++++++----------------------
>  1 files changed, 33 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
> index ef1ce2e..87b684f 100644
> --- a/drivers/net/r8169.c
> +++ b/drivers/net/r8169.c
> @@ -36,11 +36,11 @@
>  #define MODULENAME "r8169"
>  #define PFX MODULENAME ": "
>  
> -#define FIRMWARE_8168D_1	"rtl_nic/rtl8168d-1.fw"
> -#define FIRMWARE_8168D_2	"rtl_nic/rtl8168d-2.fw"
> -#define FIRMWARE_8168E_1	"rtl_nic/rtl8168e-1.fw"
> -#define FIRMWARE_8168E_2	"rtl_nic/rtl8168e-2.fw"
> -#define FIRMWARE_8105E_1	"rtl_nic/rtl8105e-1.fw"
> +#define FIRMWARE_8168D_1	"rtl_nic/rtl8168d-3.fw"
> +#define FIRMWARE_8168D_2	"rtl_nic/rtl8168d-4.fw"
> +#define FIRMWARE_8168E_1	"rtl_nic/rtl8168e-3.fw"
> +#define FIRMWARE_8168E_2	"rtl_nic/rtl8168e-4.fw"
> +#define FIRMWARE_8105E_1	"rtl_nic/rtl8105e-2.fw"

Why ?

I see it more as a calling convention to communicate with userspace
than as a place to funnel a partial version information.

>  #ifdef RTL8169_DEBUG
>  #define assert(expr) \
> @@ -594,6 +594,13 @@ struct ring_info {
>  	u8		__pad[sizeof(void *) - sizeof(u32)];
>  };
>  
> +struct fw_info {
> +	char	version[32];
> +	u32	fw_start;
> +	u32	fw_len;
> +	u8	chksum;

The chksum field is never used.

[...]
> @@ -1743,16 +1750,30 @@ static void rtl_writephy_batch(struct rtl8169_private *tp,
>  static void
>  rtl_phy_write_fw(struct rtl8169_private *tp, const struct firmware *fw)
>  {
> -	__le32 *phytable = (__le32 *)fw->data;
> +	__le32 *phytable;
>  	struct net_device *dev = tp->dev;
> -	size_t index, fw_size = fw->size / sizeof(*phytable);
> +	struct fw_info *f_info;
> +	size_t index, fw_size;

s/index/i/

>  	u32 predata, count;
> +	u8 checksum;
> +
> +	f_info = (struct fw_info *)fw->data;

It will not work very well on big-endian computers. start and len should
both use le32_to_cpu.

>  
> -	if (fw->size % sizeof(*phytable)) {
> -		netif_err(tp, probe, dev, "odd sized firmware %zd\n", fw->size);
> +	if (checksum != 0) {
> +		netif_err(tp, probe, dev, "none zero checksum(%u)\n", checksum);
>  		return;
>  	}

Nit: "checksum" is not used beyond this point. It should be possible to put
a few things in distinct functions to save some local variables.

> +	netif_info(tp, probe, dev, "firmware: %s\n", f_info->version);
> +
> +	phytable = (__le32 *)(fw->data + f_info->fw_start);
> +	fw_size = f_info->fw_len;
> +
>  	for (index = 0; index < fw_size; index++) {

It's a bit paranoid but I would feel safer if f_info->fw_len was compared
to fw->size beforehand.

[...]
> @@ -1892,14 +1913,6 @@ static void rtl_apply_firmware(struct rtl8169_private *tp)
>  		rtl_phy_write_fw(tp, fw);
>  }
>  
> -static void rtl_apply_firmware_cond(struct rtl8169_private *tp, u8 reg, u16 val)
> -{
> -	if (rtl_readphy(tp, reg) != val)
> -		netif_warn(tp, hw, tp->dev, "chipset not ready for firmware\n");
> -	else
> -		rtl_apply_firmware(tp);
> -}
> -
>  static void rtl8169s_hw_phy_config(struct rtl8169_private *tp)
>  {
>  	static const struct phy_reg phy_reg_init[] = {
> @@ -2334,10 +2347,7 @@ static void rtl8168d_1_hw_phy_config(struct rtl8169_private *tp)
>  	rtl_w1w0_phy(tp, 0x02, 0x0100, 0x0600);
>  	rtl_w1w0_phy(tp, 0x03, 0x0000, 0xe000);
>  
> -	rtl_writephy(tp, 0x1f, 0x0005);
> -	rtl_writephy(tp, 0x05, 0x001b);
> -
> -	rtl_apply_firmware_cond(tp, MII_EXPANSION, 0xbf00);
> +	rtl_apply_firmware(tp);
>  
>  	rtl_writephy(tp, 0x1f, 0x0000);
>  }
> @@ -2437,10 +2447,7 @@ static void rtl8168d_2_hw_phy_config(struct rtl8169_private *tp)
>  	rtl_writephy(tp, 0x1f, 0x0002);
>  	rtl_patchphy(tp, 0x0f, 0x0017);
>  
> -	rtl_writephy(tp, 0x1f, 0x0005);
> -	rtl_writephy(tp, 0x05, 0x001b);
> -
> -	rtl_apply_firmware_cond(tp, MII_EXPANSION, 0xb300);
> +	rtl_apply_firmware(tp);

Actually both the format and the content of the firmware are changed by the
patch.

Imho the new firmware format could include some specific string so that the
driver can identify the new firmware format and fallback to the old format
otherwise. Any fixed magic prefix would be enough as the new format mandates
the version information.

This way Linus's test machine won't risk of breaking (again...) if he builds
a new kernel without updating the firmware at the same time.

-- 
Ueimor