Subject: Re: [PATCH] stmmac: platform: fix stmmac probe failure

From: Dinh Nguyen <[email-masked]>
Date: Mon, 1 Dec 2014 14:14:31 -0600

Apologies for the noise, but it looks like Arnd has already send a patch
for this.

http://www.spinics.net/lists/netdev/msg306603.html

Dinh

On 12/1/14, 2:00 PM, [email-masked] wrote:
> From: Dinh Nguyen <[email-masked]>
> 
> The commit 571dcfde23712b ("stmmac: platform: fix default values of the filter
> bins setting") broke support for stmmac probe for all CONFIG_OF platforms.
> 
> [    0.743567] Unable to handle kernel NULL pointer dereference at virtual address 00000048
> [    0.751679] pgd = c0004000
> [    0.754384] [00000048] *pgd=00000000
> [    0.757983] Internal error: Oops: 805 [#1] SMP ARM
> [    0.762774] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.18.0-rc7 #1
> [    0.769034] task: ee86c000 ti: ee870000 task.ti: ee870000
> [    0.774429] PC is at stmmac_pltfr_probe+0x40/0x5d0
> [    0.779217] LR is at devm_ioremap_nocache+0x54/0x74
> ...
> [    0.951644] [<c0287938>] (stmmac_pltfr_probe) from [<c0234c4c>] (platform_drv_probe+0x44/0xa4)
> [    0.960250] [<c0234c4c>] (platform_drv_probe) from [<c023390c>] (driver_probe_device+0x10c/0x240)
> [    0.969113] [<c023390c>] (driver_probe_device) from [<c0233b10>] (__driver_attach+0x8c/0x90)
> [    0.977544] [<c0233b10>] (__driver_attach) from [<c02320fc>] (bus_for_each_dev+0x6c/0xa0)
> 
> The reason is that in stmmac_pltfr_probe(), the plat_dat on a CONFIG_OF
> platform is NULL until devm_kzalloc() is called to allocate plat_dat.
> 
> Signed-off-by: Dinh Nguyen <[email-masked]>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index 5b0da39..62c9e75 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -265,12 +265,6 @@ static int stmmac_pltfr_probe(struct platform_device *pdev)
>  
>  	plat_dat = dev_get_platdata(&pdev->dev);
>  
> -	/* Set default value for multicast hash bins */
> -	plat_dat->multicast_filter_bins = HASH_TABLE_SIZE;
> -
> -	/* Set default value for unicast filter entries */
> -	plat_dat->unicast_filter_entries = 1;
> -
>  	if (pdev->dev.of_node) {
>  		if (!plat_dat)
>  			plat_dat = devm_kzalloc(&pdev->dev,
> @@ -288,6 +282,12 @@ static int stmmac_pltfr_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> +	/* Set default value for multicast hash bins */
> +	plat_dat->multicast_filter_bins = HASH_TABLE_SIZE;
> +
> +	/* Set default value for unicast filter entries */
> +	plat_dat->unicast_filter_entries = 1;
> +
>  	/* Custom setup (if needed) */
>  	if (plat_dat->setup) {
>  		plat_dat->bsp_priv = plat_dat->setup(pdev);
>