Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:40128 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932079AbeADOmo (ORCPT ); Thu, 4 Jan 2018 09:42:44 -0500 From: Kalle Valo To: Emmanuel Grumbach Cc: linux-wireless@vger.kernel.org, luca@coelho.fi, sara.sharon@intel.com, stable@vger.kernel.org Subject: Re: [PATCH] iwlwifi: pcie: fix DMA memory mapping / unmapping References: <20180104071913.15470-1-emmanuel.grumbach@intel.com> Date: Thu, 04 Jan 2018 16:42:40 +0200 In-Reply-To: <20180104071913.15470-1-emmanuel.grumbach@intel.com> (Emmanuel Grumbach's message of "Thu, 4 Jan 2018 09:19:13 +0200") Message-ID: <87r2r57kin.fsf@kamboji.qca.qualcomm.com> (sfid-20180104_154257_537225_DFB30C65) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: Emmanuel Grumbach writes: > 22000 devices (previously referenced as A000) can support > short transmit queues. This means that we have less DMA > descriptors (TFD) for those shorter queues. > Previous devices must still have 256 TFDs for each queue > even if those 256 TFDs point to fewer buffers. > > When I introduced support for the short queues for 22000 > I broke older devices by assuming that they can also have > less TFDs in their queues. This led to several problems: > > 1) the payload of the commands weren't unmapped properly > which caused the SWIOTLB to complain at some point. > 2) the hardware could get confused and we get hardware > crashes. > > The corresponding bugzilla entries are: > > https://bugzilla.kernel.org/show_bug.cgi?id=198201 > https://bugzilla.kernel.org/show_bug.cgi?id=198265 > > Cc: stable@vger.kernel.org # 4.14+ > Fixes: 4ecab5616023 ("iwlwifi: pcie: support short Tx queues for A000 device family") > Reviewed-by: Sharon, Sara > Signed-off-by: Emmanuel Grumbach > --- > Hi Kalle, > > Luca is on vacation is 4.15 will be closed soon. > I am fixing here a bug that caused much troube on our side. > There are two bugzillas on it. Users on both bugs validated > this fix. > Please apply this on wireless-drivers.git directly and I'll sync > with Luca when he'll be back. Ok, I'll queue this for 4.15. -- Kalle Valo