[PATCH] ath10k: set max mtu to 1500 for sdio chip

[PATCH] ath10k: set max mtu to 1500 for sdio chip

[Wen Gong]

For sdio chip, the max credit size in firmware is 1556, the 1556
include payload, ieee80211 header, htt header, htc header. So it
need to set the max mtu to 1500 to forbidden TX packet which exceed
1500 form application.

Tested with QCA6174 SDIO with firmware
WLAN.RMH.4.4.1-00017-QCARMSWP-1.

Signed-off-by: Wen Gong <wgong@codeaurora.org>
---
 drivers/net/wireless/ath/ath10k/sdio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c
index 60849ab8088f..8aa8ebc1d8e9 100644
--- a/drivers/net/wireless/ath/ath10k/sdio.c
+++ b/drivers/net/wireless/ath/ath10k/sdio.c
@@ -2185,6 +2185,8 @@ static int ath10k_sdio_probe(struct sdio_func *func,
 	bus_params.chip_id = 0;
 	bus_params.hl_msdu_ids = true;
 
+	ar->hw->max_mtu = ETH_DATA_LEN;
+
 	ret = ath10k_core_register(ar, &bus_params);
 	if (ret) {
 		ath10k_err(ar, "failed to register driver core: %d\n", ret);
-- 
2.23.0

Re: [PATCH] ath10k: set max mtu to 1500 for sdio chip

[Kalle Valo]

Wen Gong <wgong@codeaurora.org> wrote:

> For sdio chip, the max credit size in firmware is 1556, the 1556
> include payload, ieee80211 header, htt header, htc header. So it
> need to set the max mtu to 1500 to forbidden TX packet which exceed
> 1500 form application.
> 
> Tested with QCA6174 SDIO with firmware
> WLAN.RMH.4.4.1-00017-QCARMSWP-1.
> 
> Signed-off-by: Wen Gong <wgong@codeaurora.org>
> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

Patch applied to ath-next branch of ath.git, thanks.

376a30c7c9a0 ath10k: set max mtu to 1500 for sdio chip

-- 
https://patchwork.kernel.org/patch/11263345/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: [PATCH] ath10k: set max mtu to 1500 for sdio chip

[Justin Capella]

So I understand the reasoning behind using ETH_DATA_LEN, but would it
be more future proof / obvious to the next dev to calculate the size
given the interface's parameters/defines--- I get that the values were
chosen to align with this but just worried if things were to change
over time this would not be resilient/obvious thing to fix up?

I was curious if these changes would have any impact on things like
WEP where the frames are a little larger? I came across a random post
about 80211 mdsu/mtus here
https://www.cwnp.com/forums/posts?postNum=307311 and they had
mentioned it, so it got me curious

On Tue, Nov 26, 2019 at 7:00 PM Wen Gong <wgong@codeaurora.org> wrote:
>
> For sdio chip, the max credit size in firmware is 1556, the 1556
> include payload, ieee80211 header, htt header, htc header. So it
> need to set the max mtu to 1500 to forbidden TX packet which exceed
> 1500 form application.
>
> Tested with QCA6174 SDIO with firmware
> WLAN.RMH.4.4.1-00017-QCARMSWP-1.
>
> Signed-off-by: Wen Gong <wgong@codeaurora.org>
> ---
>  drivers/net/wireless/ath/ath10k/sdio.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c
> index 60849ab8088f..8aa8ebc1d8e9 100644
> --- a/drivers/net/wireless/ath/ath10k/sdio.c
> +++ b/drivers/net/wireless/ath/ath10k/sdio.c
> @@ -2185,6 +2185,8 @@ static int ath10k_sdio_probe(struct sdio_func *func,
>         bus_params.chip_id = 0;
>         bus_params.hl_msdu_ids = true;
>
> +       ar->hw->max_mtu = ETH_DATA_LEN;
> +
>         ret = ath10k_core_register(ar, &bus_params);
>         if (ret) {
>                 ath10k_err(ar, "failed to register driver core: %d\n", ret);
> --
> 2.23.0
>