Subject: Re: [PATCH v3] ath10k: improve BDF search fallback strategy

From: Kalle Valo <[email-masked]>
Date: Tue, 10 May 2022 18:41:00 +0300

Abhishek Kumar <[email-masked]> writes:

> Board data files wrapped inside board-2.bin files are
> identified based on a combination of bus architecture,
> chip-id, board-id or variants. Here is one such example
> of a BDF entry in board-2.bin file:
> bus=snoc,qmi-board-id=67,qmi-chip-id=320,variant=GO_XXXX
> It is possible for few platforms none of the combinations
> of bus,qmi-board,chip-id or variants match, e.g. if
> board-id is not programmed and thus reads board-id=0xff,
> there won't be any matching BDF to be found. In such
> situations, the wlan will fail to enumerate.
>
> Currently, to search for BDF, there are two fallback
> boardnames creates to search for BDFs in case the full BDF
> is not found. It is still possible that even the fallback
> boardnames do not match.
>
> As an improvement, search for BDF with full BDF combination
> and perform the fallback searches by stripping down the last
> elements until a BDF entry is found or none is found for all
> possible BDF combinations.e.g.
> Search for initial BDF first then followed by reduced BDF
> names as follows:
> bus=snoc,qmi-board-id=67,qmi-chip-id=320,variant=GO_XXXX
> bus=snoc,qmi-board-id=67,qmi-chip-id=320
> bus=snoc,qmi-board-id=67
> bus=snoc
> <No BDF found>
>
> Tested-on: WCN3990/hw1.0 WLAN.HL.3.2.2.c10-00754-QCAHLSWMTPL-1
> Signed-off-by: Abhishek Kumar <[email-masked]>

[...]

>  static int ath10k_core_fetch_board_data_api_n(struct ath10k *ar,
>  					      const char *boardname,
> -					      const char *fallback_boardname1,
> -					      const char *fallback_boardname2,
>  					      const char *filename)
>  {
> -	size_t len, magic_len;
> +	size_t len, magic_len, board_len;
>  	const u8 *data;
>  	int ret;
> +	char temp_boardname[100];
> +
> +	board_len = 100 * sizeof(temp_boardname[0]);

Why not:

board_len = sizeof(temp_board-name);

That way number 100 is used only once.

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