RE: [PATCH v11 4/7] wifi: rtw88: sdio: zero the padding added to a TX transfer

[Ping-Ke Shih]

Ping-Ke Shih <pkshih@xxxxxxxxxxx> wrote:
> Luka Gejak <luka.gejak@xxxxxxxxx> wrote:
> > mac80211 reserves IEEE80211_ENCRYPT_TAILROOM, 18 bytes, and offers
> > no way for a driver to ask for more on TX; extra_tx_headroom is headroom
> > and extra_beacon_tailroom is beacons only.
> 
> You can modify mac80211 to reserve larger ndev->needed_tailroom to
> see if it can really resolve the symptom. If so, you can propose
> to add fields for tailroom like headroom:
> 
>   struct ieee80211_hw:: extra_tx_tailroom
>   struct ieee80211_local:: tx_headroom
> 

Note that the ndev->needed_tailroom isn't guaranteed by comments, so doing
some experiments by normal use case would be helpful to know if it's worth.

 *	@needed_tailroom: Extra tailroom the hardware may need, but not in all
 *			  cases can this be guaranteed. Some cases also use
 *			  LL_MAX_HEADER instead to allocate the skb

Ping-Ke