Return-path: Received: from mail-we0-f181.google.com ([74.125.82.181]:59049 "EHLO mail-we0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751997AbaFFJpK convert rfc822-to-8bit (ORCPT ); Fri, 6 Jun 2014 05:45:10 -0400 Received: by mail-we0-f181.google.com with SMTP id w61so2485695wes.40 for ; Fri, 06 Jun 2014 02:45:08 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <877g4umn7b.fsf@kamboji.qca.qualcomm.com> References: <1401904902-5842-1-git-send-email-greearb@candelatech.com> <87egz3nxdn.fsf@kamboji.qca.qualcomm.com> <5390B632.7030305@candelatech.com> <87wqcumuuw.fsf@kamboji.qca.qualcomm.com> <877g4umn7b.fsf@kamboji.qca.qualcomm.com> Date: Fri, 6 Jun 2014 11:45:08 +0200 Message-ID: (sfid-20140606_114514_697650_D939AA32) Subject: Re: [PATCH 1/4] ath10k: provide firmware crash info via debugfs. From: Michal Kazior To: Kalle Valo Cc: Ben Greear , "ath10k@lists.infradead.org" , linux-wireless Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 6 June 2014 10:55, Kalle Valo wrote: > Michal Kazior writes: > >> On 6 June 2014 08:10, Kalle Valo wrote: >>> Ben Greear writes: >> [...] >>>> I'm a bit leery of adding spin-locks in the dump routine just for >>>> this, but I can add and use a new spin-lock if you prefer. >>> >>> Why a new spinlock? I didn't review the locking requirements, but I >>> would first check ar->data_lock can be used. >>> >>>> If so, any idea if we can do the reads of the target's memory while >>>> holding a spin-lock, or would I need some temporary buffers and only >>>> lock while copying that in to the storage in the 'ar'? >>> >>> I don't see why you would need special locks for reading target's >>> memory. If there is something needed, pci.c should handle that. Michal? >> >> By definition the diagnostic window access must be serialized. We >> don't do this with locks now but rely ON driver states/sequences. We >> might have some problems lurking there already but I'd need to analyze >> it to tell for sure. > > Should that serialisation happen within pci.c? You can but that's not a requirement I guess. E.g. exchange_bmi_msg hif callback requires the caller to serialize calls. Michał