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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?OsQuE5P2mnRjnQQsThuKEnmc8J9sHGsbukJwxMZwOoQP5M332FOtf2l19lgu?= =?us-ascii?Q?7iQbjJS4cjxeKE8eO03Nv7IrZuLLIeTtgnv16ZyA7qgabd6PafCVV7OiYd/J?= =?us-ascii?Q?yhBQZ8LBDo0qXPhnYNREwzkvlGBId5vlMrM6TkHJ+1S4qyW+tOWzZDbOugt2?= =?us-ascii?Q?U4iqo7Gqt9AhsK9jZd0jrYh9FPl5cKIPQ/ad67hle7yCoYRWxbBG3MTDR0gM?= =?us-ascii?Q?7FR0TxgbkiKE0CM0ZayuFxrvuevVDwdSc4JTpoOMM8JHyPqtlcQBKFv6hG+L?= =?us-ascii?Q?IBF2Rbu2jPzcTgDeiFILdcO5EFS20jB1b8Z4lITc/4dmR32NNnc8tVvkdBj6?= =?us-ascii?Q?HhBQAD0KO1hMr1ZKPCdjctAW3oiUFkAJHAUrYt9Riw5y9Uic8H7lS5rJTmev?= =?us-ascii?Q?ZcKrxHU2r+wL1Oo06o+Zk+n+g863jA5pEJ969r45mtipY6XK46aFsp7j4BOc?= =?us-ascii?Q?HbJJuf5DpaPVroDJHXswhZYW22iuljOTTV0v6Mnzc7inKF/1hKXrhq3rzvpR?= =?us-ascii?Q?MrQwOWuBdbik2yUT9Qc8Kk6TWA5Aq5Rdq7X574sY26St9T+eZESzDKBTrHJS?= =?us-ascii?Q?5H9WqsjMY1vdjWVByBZS0eVNj8Mgw8XNUjTwMzbjImfAuZrqS1Uc5HswAJ2W?= =?us-ascii?Q?bK4oKC0Mv95lxa9ms5NQk+OOTk+eg/CILznO+jVT2vMOBsIQImIhSvq4ZfZ7?= =?us-ascii?Q?1wY4SX/mOXY9YSAMWUGEmss8As8/IdJTPU1IVC7uRp1WmWfr8tFovVlR62jt?= =?us-ascii?Q?JVeJmzIfJnZkxPe5+/Qdcig1BY+n0f5apVuaMtQrGrMoCiqBiiDteYHAkWlL?= =?us-ascii?Q?/mHD4aY1hqMS+D1nLUPAJdIwAZtohQgJvArpgnvzvb+zp/EqRyXG8axecrJt?= =?us-ascii?Q?e2ZFE/+WuvOBpwui5LKY2Igpa4sy0yfEUwRC2qZXXyNMUdg84zT5Bghoa/m9?= =?us-ascii?Q?3mkoJawYsc9a1jl4MSwrWFrWcWV+dlQFY+cb92U3Vy7b2T3mQltC+PCUiBrp?= =?us-ascii?Q?5D9AE6UW18aziTvbkDy462HeIbNIkyXpUvXvOZtxLbuG5EziVgEQkE7mL9lI?= =?us-ascii?Q?r1rf+XbAN+NnMpi+RgvgE/OoGwaEsN4pmuxmD8RXaU3G6lDJnlpLqzhxjYDe?= =?us-ascii?Q?YP4334TJyV3EgAbj51lJ0Br3wpRVlmllIW7m3gfRn171s3DISL//pEupiYyK?= =?us-ascii?Q?IERSNCw66RHnbjkefH8h0KR2GqXU5mjWKMiqS+YvFEOR1U5yF0GLzjN/tagM?= =?us-ascii?Q?MF4LZTXr55ZmqifaaGnBSOFx/RF3YJ0Eo6AJrg3kL5XjJzqTFilqipITqN6V?= =?us-ascii?Q?M+P+/7ssiFOS/UAvgdmr1rdm3UqJpveP013y6NRw2gW4zPd1dHPRkVEhQL/6?= =?us-ascii?Q?iD3Q76P4H8GcONuFSQdxy7ajgmiMaRqdpGmNsQ4MXGqRgbkeePGaevNX8aNh?= =?us-ascii?Q?brJ4tXYwXsHCrk1ivSqMAAMhUBAI1/clSGboTUl9n7HMR0iavrTzHoZUAdBJ?= =?us-ascii?Q?h5qJfDvN+DL5zKXgLAmTVpQRQoLUcNGdlddz+R1T4npmIapqWBLspzJd78n6?= =?us-ascii?Q?Mvz0zzu2eoSrNsd6AcbG399yRdpmuFt39IUjw9Zs?= X-MS-Exchange-CrossTenant-Network-Message-Id: 75484636-9554-4ecb-8d2e-08dad1788928 X-MS-Exchange-CrossTenant-AuthSource: SA1PR11MB6733.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Nov 2022 19:41:25.5326 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: sSHZGXkZUHKG6z8DptFaWLFXVVq5J6yQitWql02vyJkWko4KdkQMJxBu8eeWO9O2hVvBQ5VBS2XHJA2oukB5DQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA2PR11MB5098 X-OriginatorOrg: intel.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 28, 2022 at 09:51:47AM -0800, Alison Schofield wrote: > On Sun, Nov 27, 2022 at 08:03:37PM -0800, Ira Weiny wrote: > > From: Ira Weiny > > > > pci_doe_flush_mb() does not work and is currently unused. > > > > It does not work because each struct doe_mb is managed as part of the > > PCI device. They can't go away as long as the PCI device exists. > > pci_doe_flush_mb() was set up to flush the workqueue and prevent any > > further submissions to the mailboxes when the PCI device goes away. > > Unfortunately, this was fundamentally flawed. There was no guarantee > > that a struct doe_mb remained after pci_doe_flush_mb() returned. > > Therefore, the doe_mb state could be invalid when those threads waiting > > on the workqueue were flushed. > > > > Fortunately the current code is safe because all callers make a > > synchronous call to pci_doe_submit_task() and maintain a reference on > > the PCI device. Therefore pci_doe_flush_mb() is effectively unused. > > > > Rather than attempt to fix pci_doe_flush_mb() just remove the dead code > > around pci_doe_flush_mb(). > > The commit message says "Remove ...." and the commit log only > talks about removing code, yet an msleep() is added. > Can those be clearer? :-/ I'm struggling a bit with this comment. The patch focus is on removing an unneeded and effectively unused function. (It is called but not in a way that would cause any running task to be aborted.) The replacement of pci_doe_wait() with msleep_interruptible() is a side effect and I don't think belongs in the one liner. I suppose something like this might work? PCI/DOE: Replace broken task cancellation with msleep I guess that makes some sense. Combined with Ming's suggestion we are still allowing task cancellation but from a signal rather than PCI device removal. Ira > > > > > Cc: Lukas Wunner > > Cc: Jonathan Cameron > > Signed-off-by: Ira Weiny > > > > --- > > Changes from V2: > > Lukas > > Clarify commit message. > > Jonathan > > Add comment for changed poll interval. > > --- > > drivers/pci/doe.c | 49 +++++------------------------------------------ > > 1 file changed, 5 insertions(+), 44 deletions(-) > > > > diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c > > index e402f05068a5..685e7d26c7eb 100644 > > --- a/drivers/pci/doe.c > > +++ b/drivers/pci/doe.c > > @@ -24,10 +24,10 @@ > > > > /* Timeout of 1 second from 6.30.2 Operation, PCI Spec r6.0 */ > > #define PCI_DOE_TIMEOUT HZ > > -#define PCI_DOE_POLL_INTERVAL (PCI_DOE_TIMEOUT / 128) > > +/* Interval to poll mailbox status */ > > +#define PCI_DOE_POLL_INTERVAL_MSECS 8 > > > > -#define PCI_DOE_FLAG_CANCEL 0 > > -#define PCI_DOE_FLAG_DEAD 1 > > +#define PCI_DOE_FLAG_DEAD 0 > > > > /** > > * struct pci_doe_mb - State for a single DOE mailbox > > @@ -53,15 +53,6 @@ struct pci_doe_mb { > > unsigned long flags; > > }; > > > > -static int pci_doe_wait(struct pci_doe_mb *doe_mb, unsigned long timeout) > > -{ > > - if (wait_event_timeout(doe_mb->wq, > > - test_bit(PCI_DOE_FLAG_CANCEL, &doe_mb->flags), > > - timeout)) > > - return -EIO; > > - return 0; > > -} > > - > > static void pci_doe_write_ctrl(struct pci_doe_mb *doe_mb, u32 val) > > { > > struct pci_dev *pdev = doe_mb->pdev; > > @@ -82,12 +73,9 @@ static int pci_doe_abort(struct pci_doe_mb *doe_mb) > > pci_doe_write_ctrl(doe_mb, PCI_DOE_CTRL_ABORT); > > > > do { > > - int rc; > > u32 val; > > > > - rc = pci_doe_wait(doe_mb, PCI_DOE_POLL_INTERVAL); > > - if (rc) > > - return rc; > > + msleep_interruptible(PCI_DOE_POLL_INTERVAL_MSECS); > > pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val); > > > > /* Abort success! */ > > @@ -278,11 +266,7 @@ static void doe_statemachine_work(struct work_struct *work) > > signal_task_abort(task, -EIO); > > return; > > } > > - rc = pci_doe_wait(doe_mb, PCI_DOE_POLL_INTERVAL); > > - if (rc) { > > - signal_task_abort(task, rc); > > - return; > > - } > > + msleep_interruptible(PCI_DOE_POLL_INTERVAL_MSECS); > > goto retry_resp; > > } > > > > @@ -383,21 +367,6 @@ static void pci_doe_destroy_workqueue(void *mb) > > destroy_workqueue(doe_mb->work_queue); > > } > > > > -static void pci_doe_flush_mb(void *mb) > > -{ > > - struct pci_doe_mb *doe_mb = mb; > > - > > - /* Stop all pending work items from starting */ > > - set_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags); > > - > > - /* Cancel an in progress work item, if necessary */ > > - set_bit(PCI_DOE_FLAG_CANCEL, &doe_mb->flags); > > - wake_up(&doe_mb->wq); > > - > > - /* Flush all work items */ > > - flush_workqueue(doe_mb->work_queue); > > -} > > - > > /** > > * pcim_doe_create_mb() - Create a DOE mailbox object > > * > > @@ -450,14 +419,6 @@ struct pci_doe_mb *pcim_doe_create_mb(struct pci_dev *pdev, u16 cap_offset) > > return ERR_PTR(rc); > > } > > > > - /* > > - * The state machine and the mailbox should be in sync now; > > - * Set up mailbox flush prior to using the mailbox to query protocols. > > - */ > > - rc = devm_add_action_or_reset(dev, pci_doe_flush_mb, doe_mb); > > - if (rc) > > - return ERR_PTR(rc); > > - > > rc = pci_doe_cache_protocols(doe_mb); > > if (rc) { > > pci_err(pdev, "[%x] failed to cache protocols : %d\n", > > -- > > 2.37.2 > >