[PATCH] net-bnx2x: Fix byte order problem on NVRAM writes

[PATCH] net-bnx2x: Fix byte order problem on NVRAM writes

[Nate Klein]

Tested:
    ethtool -e eth0 raw on >first.nvram
    ethtool -E eth0 <first.nvram
    ethtool -e eth0 raw on >second.nvram
    cmp first.nvram second.nvram || ethtool -E eth0 <second.nvram
    (No output means pass.)
---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c
index 8213cc8..35671fb 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c
@@ -1549,7 +1549,7 @@ static int bnx2x_nvram_write_dword(struct bnx2x *bp, u32 offset, u32 val,
 	REG_WR(bp, MCP_REG_MCPR_NVM_COMMAND, MCPR_NVM_COMMAND_DONE);
 
 	/* write the data */
-	REG_WR(bp, MCP_REG_MCPR_NVM_WRITE, val);
+	REG_WR(bp, MCP_REG_MCPR_NVM_WRITE, cpu_to_be32(val));
 
 	/* address of the NVRAM to write to */
 	REG_WR(bp, MCP_REG_MCPR_NVM_ADDR,
-- 
1.8.4

RE: [PATCH] net-bnx2x: Fix byte order problem on NVRAM writes

[Yuval Mintz]

> Tested:
>     ethtool -e eth0 raw on >first.nvram
>     ethtool -E eth0 <first.nvram
>     ethtool -e eth0 raw on >second.nvram
>     cmp first.nvram second.nvram || ethtool -E eth0 <second.nvram
>     (No output means pass.)

Hi Nate,

We're aware of this `bug' for some time - we've encountered it when
trying to fix the endian sparse warnings in the driver.

Sadly, there are already existing user applications that assume that this is 
the driver's behaviour - i.e., those applications prepare their buffers in a 
manner which assumes the endian of the writes; changing this write will 
cause those tools to break.
That's why we haven't fixed the issue before, and cannot support such a
fix. We're more than willing to document it somewhere, if that seems 
useful to anyone.

Thanks,
Yuval

> ---
>  drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c
> b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c
> index 8213cc8..35671fb 100644
> --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c
> +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c
> @@ -1549,7 +1549,7 @@ static int bnx2x_nvram_write_dword(struct bnx2x
> *bp, u32 offset, u32 val,
>  	REG_WR(bp, MCP_REG_MCPR_NVM_COMMAND,
> MCPR_NVM_COMMAND_DONE);
> 
>  	/* write the data */
> -	REG_WR(bp, MCP_REG_MCPR_NVM_WRITE, val);
> +	REG_WR(bp, MCP_REG_MCPR_NVM_WRITE, cpu_to_be32(val));
> 
>  	/* address of the NVRAM to write to */
>  	REG_WR(bp, MCP_REG_MCPR_NVM_ADDR,
> --