Re: [PATCH 2/3] brcmfmac: return error when getting invalid max_flowrings from dongle

[Arend Van Spriel <aspriel@gmail.com>]

On 9/29/2022 5:10 AM, Ian Lin wrote:
> From: Wright Feng <wright.feng@cypress.com>
> 
> When firmware hit trap at initialization, host will read abnormal
> max_flowrings number from dongle, and it will cause kernel panic when
> doing iowrite to initialize dongle ring.
> To detect this error at early stage, we directly return error when getting
> invalid max_flowrings(>256).
> 
> Signed-off-by: Wright Feng <wright.feng@cypress.com>
> Signed-off-by: Chi-hsien Lin <chi-hsien.lin@cypress.com>
> Signed-off-by: Ian Lin <ian.lin@infineon.com>
> ---
>   drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
> index 2b7ebbd7b5b4..1becd50038ab 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
> @@ -1228,6 +1228,10 @@ static int brcmf_pcie_init_ringbuffers(struct brcmf_pciedev_info *devinfo)
>   				BRCMF_NROF_H2D_COMMON_MSGRINGS;
>   		max_completionrings = BRCMF_NROF_D2H_COMMON_MSGRINGS;
>   	}
> +	if (max_flowrings > 256) {
This limit is a bit of a magic value. I do know there are chipsets that 
support more that 256 flowrings so this is a hard limitation. I should 
really get the multi-vendor support in place so we can have the 
limitation only for Infineon/Cypress chips. I will try to revive that 
thread.

Regards,
Arend