From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x234.google.com (mail-pf0-x234.google.com [IPv6:2607:f8b0:400e:c00::234]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3qpzbc5FwfzDq60 for ; Tue, 19 Apr 2016 19:04:28 +1000 (AEST) Received: by mail-pf0-x234.google.com with SMTP id 184so4959060pff.0 for ; Tue, 19 Apr 2016 02:04:28 -0700 (PDT) Subject: Re: [PATCH v8 35/45] powerpc/powernv: Fundamental reset in pnv_pci_reset_secondary_bus() To: Gavin Shan , linuxppc-dev@lists.ozlabs.org References: <1455680668-23298-1-git-send-email-gwshan@linux.vnet.ibm.com> <1455680668-23298-36-git-send-email-gwshan@linux.vnet.ibm.com> Cc: linux-pci@vger.kernel.org, devicetree@vger.kernel.org, benh@kernel.crashing.org, mpe@ellerman.id.au, dja@axtens.net, bhelgaas@google.com, robherring2@gmail.com, grant.likely@linaro.org From: Alexey Kardashevskiy Message-ID: <5715F493.2030002@ozlabs.ru> Date: Tue, 19 Apr 2016 19:04:19 +1000 MIME-Version: 1.0 In-Reply-To: <1455680668-23298-36-git-send-email-gwshan@linux.vnet.ibm.com> Content-Type: text/plain; charset=koi8-r; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 02/17/2016 02:44 PM, Gavin Shan wrote: > In pnv_pci_reset_secondary_bus(), we should issue fundamental reset > if any one subordinate device of the specified bus is requesting that. > Otherwise, the device might not come up after the reset. > > Signed-off-by: Gavin Shan Reviewed-by: Alexey Kardashevskiy Out of curiosity - what does "fundamental" reset actually do? > --- > arch/powerpc/platforms/powernv/eeh-powernv.c | 21 ++++++++++++++++++++- > 1 file changed, 20 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c > index 593b8dc..c7454ba 100644 > --- a/arch/powerpc/platforms/powernv/eeh-powernv.c > +++ b/arch/powerpc/platforms/powernv/eeh-powernv.c > @@ -866,9 +866,28 @@ static int pnv_eeh_bridge_reset(struct pci_dev *dev, int option) > return 0; > } > > +static int pnv_pci_dev_reset_type(struct pci_dev *pdev, void *data) > +{ > + int *freset = data; > + > + /* > + * Stop the iteration immediately if there has any one > + * PCI device requesting fundamental reset. > + */ > + *freset |= pdev->needs_freset; > + return *freset; > +} > + > void pnv_pci_reset_secondary_bus(struct pci_dev *dev) > { > - pnv_eeh_bridge_reset(dev, EEH_RESET_HOT); > + int option, freset = 0; > + > + if (dev->subordinate) > + pci_walk_bus(dev->subordinate, > + pnv_pci_dev_reset_type, &freset); > + > + option = freset ? EEH_RESET_FUNDAMENTAL : EEH_RESET_HOT; > + pnv_eeh_bridge_reset(dev, option); > pnv_eeh_bridge_reset(dev, EEH_RESET_DEACTIVATE); > } > > -- Alexey