From: "Alastair D'Silva" <alastair@au1.ibm.com>
To: Frederic Barrat <fbarrat@linux.ibm.com>,
linuxppc-dev@lists.ozlabs.org, andrew.donnellan@au1.ibm.com,
clombard@linux.ibm.com
Cc: groug@kaod.org
Subject: Re: [PATCH 01/11] powerpc/powernv/ioda: Fix ref count for devices with their own PE
Date: Tue, 10 Sep 2019 10:20:56 +1000 [thread overview]
Message-ID: <02d7bbc21e915012efe3c0178a4c0327cb016822.camel@au1.ibm.com> (raw)
In-Reply-To: <20190909154600.19917-2-fbarrat@linux.ibm.com>
On Mon, 2019-09-09 at 17:45 +0200, Frederic Barrat wrote:
> Taking a reference on the pci_dev structure was required with initial
> commit 184cd4a3b962 ("powerpc/powernv: PCI support for p7IOC under
> OPAL v2"), where we were storing the pci_dev in the pci_dn structure.
>
> However, the pci_dev was later removed from the pci_dn structure, but
> the reference was kept. See commit 902bdc57451c
> ("powerpc/powernv/idoa:
> Remove unnecessary pcidev from pci_dn").
>
> The pnv_ioda_pe structure life cycle is the same as the pci_dev
> structure, the PE is freed when the device is released. So we don't
> need a reference for the pci_dev stored in the PE, otherwise the
> pci_dev will never be released. Which is not really a surprise as the
> comment (removed here as no longer needed) was stating as much.
>
> Fixes: 902bdc57451c ("powerpc/powernv/idoa: Remove unnecessary pcidev
> from pci_dn")
> Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
> ---
> arch/powerpc/platforms/powernv/pci-ioda.c | 11 +----------
> 1 file changed, 1 insertion(+), 10 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c
> b/arch/powerpc/platforms/powernv/pci-ioda.c
> index d8080558d020..92767f006f20 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -1062,14 +1062,6 @@ static struct pnv_ioda_pe
> *pnv_ioda_setup_dev_PE(struct pci_dev *dev)
> return NULL;
> }
>
> - /* NOTE: We get only one ref to the pci_dev for the pdn, not
> for the
> - * pointer in the PE data structure, both should be destroyed
> at the
> - * same time. However, this needs to be looked at more closely
> again
> - * once we actually start removing things (Hotplug, SR-IOV,
> ...)
> - *
> - * At some point we want to remove the PDN completely anyways
> - */
> - pci_dev_get(dev);
> pdn->pe_number = pe->pe_number;
> pe->flags = PNV_IODA_PE_DEV;
> pe->pdev = dev;
> @@ -1084,7 +1076,6 @@ static struct pnv_ioda_pe
> *pnv_ioda_setup_dev_PE(struct pci_dev *dev)
> pnv_ioda_free_pe(pe);
> pdn->pe_number = IODA_INVALID_PE;
> pe->pdev = NULL;
> - pci_dev_put(dev);
> return NULL;
> }
>
> @@ -1228,7 +1219,7 @@ static struct pnv_ioda_pe
> *pnv_ioda_setup_npu_PE(struct pci_dev *npu_pdev)
> */
> dev_info(&npu_pdev->dev,
> "Associating to existing PE %x\n",
> pe_num);
> - pci_dev_get(npu_pdev);
> + pci_dev_get(npu_pdev); // still needed after
> 902bdc57451c ?
> npu_pdn = pci_get_pdn(npu_pdev);
> rid = npu_pdev->bus->number << 8 | npu_pdn-
> >devfn;
> npu_pdn->pe_number = pe_num;
Reviewed-by: Alastair D'Silva <alastair@d-silva.org>
--
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819
next prev parent reply other threads:[~2019-09-10 0:22 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-09 15:45 [PATCH 00/11] opencapi: enable card reset and link retraining Frederic Barrat
2019-09-09 15:45 ` [PATCH 01/11] powerpc/powernv/ioda: Fix ref count for devices with their own PE Frederic Barrat
2019-09-10 0:20 ` Alastair D'Silva [this message]
2019-09-26 16:44 ` Andrew Donnellan
2019-09-26 17:15 ` Frederic Barrat
2019-09-27 6:54 ` Alexey Kardashevskiy
2019-11-12 17:38 ` Frederic Barrat
2019-11-18 1:04 ` Alistair Popple
2019-11-18 1:24 ` Oliver O'Halloran
2019-11-18 2:36 ` Alistair Popple
2019-11-18 18:21 ` Frederic Barrat
2019-09-09 15:45 ` [PATCH 02/11] powerpc/powernv/ioda: Protect PE list Frederic Barrat
2019-09-10 0:34 ` Alastair D'Silva
2019-11-19 12:55 ` Frederic Barrat
2019-11-19 13:22 ` Oliver O'Halloran
2019-11-19 14:36 ` Frederic Barrat
2019-11-19 5:55 ` Andrew Donnellan
2019-09-09 15:45 ` [PATCH 03/11] powerpc/powernv/ioda: set up PE on opencapi device when enabling Frederic Barrat
2019-09-10 0:38 ` Alastair D'Silva
2019-09-27 16:43 ` Andrew Donnellan
2019-09-09 15:45 ` [PATCH 04/11] powerpc/powernv/ioda: Release opencapi device Frederic Barrat
2019-09-10 0:56 ` Alastair D'Silva
2019-11-19 17:32 ` Frederic Barrat
2019-11-19 7:08 ` Andrew Donnellan
2019-09-09 15:45 ` [PATCH 05/11] powerpc/powernv/ioda: Find opencapi slot for a device node Frederic Barrat
2019-09-10 0:57 ` Alastair D'Silva
2019-11-19 1:26 ` Andrew Donnellan
2019-11-19 14:33 ` Frederic Barrat
2019-09-09 15:45 ` [PATCH 06/11] pci/hotplug/pnv-php: Remove erroneous warning Frederic Barrat
2019-09-10 0:58 ` Alastair D'Silva
2019-11-19 5:00 ` Andrew Donnellan
2019-09-09 15:45 ` [PATCH 07/11] pci/hotplug/pnv-php: Improve error msg on power state change failure Frederic Barrat
2019-09-10 0:59 ` Alastair D'Silva
2019-11-19 2:23 ` Andrew Donnellan
2019-09-09 15:45 ` [PATCH 08/11] pci/hotplug/pnv-php: Register opencapi slots Frederic Barrat
2019-09-10 1:00 ` Alastair D'Silva
2019-11-19 5:18 ` Andrew Donnellan
2019-11-19 15:15 ` Frederic Barrat
2019-09-09 15:45 ` [PATCH 09/11] pci/hotplug/pnv-php: Relax check when disabling slot Frederic Barrat
2019-09-10 1:00 ` Alastair D'Silva
2019-09-27 15:56 ` Andrew Donnellan
2019-09-09 15:45 ` [PATCH 10/11] pci/hotplug/pnv-php: Wrap warnings in macro Frederic Barrat
2019-09-10 1:03 ` Alastair D'Silva
2019-09-26 17:18 ` Andrew Donnellan
2019-09-09 15:46 ` [PATCH 11/11] ocxl: Add PCI hotplug dependency to Kconfig Frederic Barrat
2019-09-10 1:03 ` Alastair D'Silva
2019-09-26 17:11 ` Andrew Donnellan
2019-09-24 4:24 ` [PATCH 00/11] opencapi: enable card reset and link retraining Alexey Kardashevskiy
2019-09-24 6:39 ` Frederic Barrat
2019-09-25 0:20 ` Alexey Kardashevskiy
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