Return-path: Received: from mail-ie0-f180.google.com ([209.85.223.180]:36013 "EHLO mail-ie0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752814AbbFAXsy (ORCPT ); Mon, 1 Jun 2015 19:48:54 -0400 Received: by ieclw1 with SMTP id lw1so26107283iec.3 for ; Mon, 01 Jun 2015 16:48:54 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1433190860.3505.16.camel@sipsolutions.net> References: <1433187498-15124-1-git-send-email-cfliu.tw@gmail.com> <1433190860.3505.16.camel@sipsolutions.net> From: "Liu CF/TW" Date: Mon, 1 Jun 2015 16:48:13 -0700 Message-ID: (sfid-20150602_014857_820253_30E91B15) Subject: Re: [PATCH] mac80211: support IEEE80211_KEY_FLAG_RESERVE_TAILROOM for CCMP and TKIP. To: Johannes Berg Cc: linux-wireless@vger.kernel.org, Kalle Valo Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi Johannes, yes indeed you are right. This change is indeed not required/right. It's the special sw crypto path I'm working on in ath10k that resulted in the ieee80211_key_enable_hw_accel() code being skipped. I will fix this in ath10k driver internally. Thanks David On Mon, Jun 1, 2015 at 1:34 PM, Johannes Berg wrote: > On Mon, 2015-06-01 at 12:38 -0700, David Liu wrote: >> The change reserves neccessary tailroom in CCMP and TKIP if required by >> drivers that sets IEEE80211_KEY_FLAG_RESERVE_TAILROOM. For example, >> ath10k HW engine in raw Tx/Rx encap mode requires SW reserve MIC/ICV space. > > I don't think this makes all that much sense. The flag is already > honoured today to actually leave enough tailroom in the SKB, and the > remainder of the code can very easily be done in the driver (in fact, if > you have a half-decent DMA engine, it's far more efficient to *not* set > this flag!) > > You're also breaking other drivers with your change. Just do it in the > driver. > > johannes >