Re: [PATCH V3 9/9] powerpc/eeh: handle VF PE properly

From: Wei Yang <weiyang@linux.vnet.ibm.com>
To: Gavin Shan <gwshan@linux.vnet.ibm.com>
Cc: Wei Yang <weiyang@linux.vnet.ibm.com>,
	bhelgaas@google.com, linuxppc-dev@lists.ozlabs.org,
	linux-pci@vger.kernel.org
Subject: Re: [PATCH V3 9/9] powerpc/eeh: handle VF PE properly
Date: Thu, 14 May 2015 18:02:50 +0800	[thread overview]
Message-ID: <20150514100250.GB12847@richard> (raw)
In-Reply-To: <20150513011630.GA8973@gwshan>

On Wed, May 13, 2015 at 11:16:30AM +1000, Gavin Shan wrote:
>> 	 * Actually, we should remove the PCI bridges as well.
>>@@ -416,7 +450,7 @@ static void *eeh_rmv_device(void *data, void *userdata)
>> 	driver = eeh_pcid_get(dev);
>> 	if (driver) {
>> 		eeh_pcid_put(dev);
>>-		if (driver->err_handler)
>>+		if (removed && driver->err_handler)
>> 			return NULL;
>> 	}
>>
>>@@ -425,11 +459,21 @@ static void *eeh_rmv_device(void *data, void *userdata)
>> 		 pci_name(dev));
>> 	edev->bus = dev->bus;
>> 	edev->mode |= EEH_DEV_DISCONNECTED;
>>-	(*removed)++;
>>-
>>-	pci_lock_rescan_remove();
>>-	pci_stop_and_remove_bus_device(dev);
>>-	pci_unlock_rescan_remove();
>>+	if (removed)
>>+		(*removed)++;
>>+
>>+#ifdef CONFIG_PCI_IOV
>>+	if (edev->mode & EEH_DEV_VF) {
>>+		pci_iov_virtfn_remove(edev->physfn, pdn->vf_index, 0);
>>+		edev->pdev = NULL;
>>+		pdn->pe_number = IODA_INVALID_PE;
>
>Setting the PE number to invalid one seems not correct because the PE
>is still consumed by the VF's RID.
>

In commit 781a868f3136, we introduce the check of pdn->pe_number in
pnv_pci_dma_dev_setup(). Since VFs are create/released dynamically, we need to
delay the bind between PE and the device. Then to avoid rebind it, we check
the pdn->pe_number. The WARN_ON() is what you suggested.

So if don't clear the pe_number here, we break that rule.

-- 
Richard Yang
Help you, Help me