Return-path: Received: from mx1.redhat.com ([209.132.183.28]:26499 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753738AbaBDTIH (ORCPT ); Tue, 4 Feb 2014 14:08:07 -0500 Date: Tue, 4 Feb 2014 20:09:36 +0100 From: Alexander Gordeev To: Kalle Valo Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-wireless@vger.kernel.org, ath10k@lists.infradead.org Subject: Re: [PATCH 1/3] ath10k: Get rid of superfluous call to pci_disable_msi() Message-ID: <20140204190935.GA1430@dhcp-26-207.brq.redhat.com> (sfid-20140204_200828_672846_63CC1CD2) References: <20140130134819.GA31909@dhcp-26-207.brq.redhat.com> <87y51qohjn.fsf@kamboji.qca.qualcomm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <87y51qohjn.fsf@kamboji.qca.qualcomm.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, Feb 04, 2014 at 08:32:12PM +0200, Kalle Valo wrote: > Alexander Gordeev writes: > > > Signed-off-by: Alexander Gordeev > > --- > > drivers/net/wireless/ath/ath10k/pci.c | 2 -- > > 1 files changed, 0 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c > > index 29fd197..6525e1f 100644 > > --- a/drivers/net/wireless/ath/ath10k/pci.c > > +++ b/drivers/net/wireless/ath/ath10k/pci.c > > @@ -2414,8 +2414,6 @@ static int ath10k_pci_init_irq(struct ath10k *ar) > > ret = pci_enable_msi_block(ar_pci->pdev, ar_pci->num_msi_intrs); > > if (ret == 0) > > return 0; > > - if (ret > 0) > > - pci_disable_msi(ar_pci->pdev); > > I don't understand how this is superfluous. When I read the > documentation for pci_enable_msi_block() it states that if it can't > allocate all requests, it will return the number requests it could > allocate. And in that case we want to fall back other modes. > > Am I missing something? Yep. The documentation states 'could have been allocated', not 'could allocate'. IOW, MSIs are *not* enabled if a positive value returned. The code I changed tries to disable MSIs in such case, although it is not necessary, nor required. Just superfluous. HTH. -- Regards, Alexander Gordeev agordeev@redhat.com