Re: [PATCH] wifi: brcmfmac: set F2 blocksize to 256 for BCM43752

[Arend van Spriel]

On 13/07/2026 10:50, LiangCheng Wang wrote:
> The BCM43752 is not reliable with the default 512-byte SDIO function 2
> block size: on an i.MX8MP board with an AMPAK AP6275S module at
> SDR104 / 200 MHz, an iperf TX stress test kills WLAN within seconds:
>
>    mmc_submit_one: CMD53 sg block write failed -84
>    brcmf_sdio_dpc: failed backplane access over SDIO, halting operation
>
> Commit d2587c57ffd8 ("brcmfmac: add 43752 SDIO ids and initialization")
> set up the 43752 like the 4373 for the F2 watermark but missed the F2
> block size, which the 4373 limits to 256 bytes. The vendor driver
> (bcmdhd) also programs a 256-byte F2 block size for this chip and runs
> the same hardware without errors.
>
> Group the 43752 with the 4373, matching the F2 watermark handling.
> With this change a 10-minute bidirectional iperf3 soak completes with
> zero SDIO errors at ~270 Mbit/s in each direction.
>
> Fixes: d2587c57ffd8 ("brcmfmac: add 43752 SDIO ids and initialization")
> Cc: stable@xxxxxxxxxxxxxxx # <= 6.16 needs the CYPRESS_43752 id name

Looks good to me but the stable instruction looks confusion. What do you 
mean. If there is no 43752 support there is no need for this patch, right?

Regards,
Arend

> Signed-off-by: LiangCheng Wang <zaq14760@xxxxxxxxx>
> ---