Re: [PATCH v2] brcmfmac: Transform compatible string for FW loading

[Hans de Goede]

Hi,

On 6/29/20 1:01 PM, matthias.bgg@xxxxxxxxxx wrote:
> From: Matthias Brugger <mbrugger@xxxxxxxx>
>
> The driver relies on the compatible string from DT to determine which
> FW configuration file it should load. The DTS spec allows for '/' as
> part of the compatible string. We change this to '-' so that we will
> still be able to load the config file, even when the compatible has a
> '/'. This fixes explicitly the firmware loading for
> "solidrun,cubox-i/q".
>
> Signed-off-by: Matthias Brugger <mbrugger@xxxxxxxx>
>
> ---
>
> Changes in v2:
> - use strscpy instead of strncpy (Hans de Goede)
> - use strlen(tmp) + 1 for allocation (Hans de Goede, kernel test robot)
>
>   .../wireless/broadcom/brcm80211/brcmfmac/of.c  | 18 +++++++++++++++---
>   1 file changed, 15 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> index b886b56a5e5a..5f0ebaf4d64e 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> @@ -17,7 +17,6 @@ void brcmf_of_probe(struct device *dev, enum brcmf_bus_type bus_type,
>   {
>   	struct brcmfmac_sdio_pd *sdio = &settings->bus.sdio;
>   	struct device_node *root, *np = dev->of_node;
> -	struct property *prop;
>   	int irq;
>   	u32 irqf;
>   	u32 val;
> @@ -25,8 +24,21 @@ void brcmf_of_probe(struct device *dev, enum brcmf_bus_type bus_type,
>   	/* Set board-type to the first string of the machine compatible prop */
>   	root = of_find_node_by_path("/");
>   	if (root) {
> -		prop = of_find_property(root, "compatible", NULL);
> -		settings->board_type = of_prop_next_string(prop, NULL);
> +		int i;
> +		char *board_type;
> +		const char *tmp;
> +
> +		of_property_read_string_index(root, "compatible", 0, &tmp);
> +
> +		/* get rid of '/' in the compatible string to be able to find the FW */
> +		board_type = devm_kzalloc(dev, strlen(tmp) + 1, GFP_KERNEL);
> +		strscpy(board_type, tmp, sizeof(board_type));

sizeof(board_type) == sizeof(char *) == 4 or 8 bytes, which is not what you
want. Maybe store strlen() + 1 in an int len to avoid having to call it 2 times?

> +		for (i = 0; i < strlen(board_type); i++) {

And here you probably want to use:

		for (i = 0; board_type[i]; i++) {

Rather then calling strlen many times again (in theory each step
through the loop).

Regards,

Hans



> +			if (board_type[i] == '/')
> +				board_type[i] = '-';
> +		}
> +		settings->board_type = board_type;
> +
>   		of_node_put(root);
>   	}
>