From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752683AbeC2KDK (ORCPT ); Thu, 29 Mar 2018 06:03:10 -0400 Received: from fllnx209.ext.ti.com ([198.47.19.16]:44751 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752497AbeC2KDI (ORCPT ); Thu, 29 Mar 2018 06:03:08 -0400 Subject: Re: [PATCH v5 10/12] PCI: endpoint: Make sure that BAR_5 does not have 64-bit flag set when clearing To: Niklas Cassel , , Lorenzo Pieralisi , Bjorn Helgaas References: <20180328115018.31921-1-niklas.cassel@axis.com> <20180328115018.31921-11-niklas.cassel@axis.com> CC: Niklas Cassel , , From: Kishon Vijay Abraham I Message-ID: Date: Thu, 29 Mar 2018 15:32:55 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20180328115018.31921-11-niklas.cassel@axis.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 28 March 2018 05:20 PM, Niklas Cassel wrote: > Since a 64-bit BAR consists of a BAR pair, and since there is no > BAR after BAR_5, BAR_5 cannot be 64-bits wide. > > This sanity check is done in pci_epc_clear_bar(), so that we don't need > to do this sanity check in all epc->ops->clear_bar() implementations. > > Signed-off-by: Niklas Cassel Acked-by: Kishon Vijay Abraham I > --- > Kishon made a review comment that he wanted this: > https://marc.info/?l=linux-kernel&m=152161168226203 > > Personally, I don't think that this check is needed, > since pci_epc_set_bar() already does this check, > and no one should modify the flags after pci_epc_set_bar() > has been called. > > If everyone agrees, then this patch could be dropped. > > drivers/pci/endpoint/pci-epc-core.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c > index eccc942043cb..b0ee42739c3c 100644 > --- a/drivers/pci/endpoint/pci-epc-core.c > +++ b/drivers/pci/endpoint/pci-epc-core.c > @@ -285,7 +285,9 @@ void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no, > { > unsigned long flags; > > - if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) > + if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions || > + (epf_bar->barno == BAR_5 && > + epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64)) > return; > > if (!epc->ops->clear_bar) >