From:   "Wu, Wentong" <wentong.wu@intel.com>
To:     Hillf Danton <hdanton@sina.com>
CC:     "mchehab@kernel.org" <mchehab@kernel.org>,
        "sakari.ailus@linux.intel.com" <sakari.ailus@linux.intel.com>,
        "linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
        "Pandruvada, Srinivas" <srinivas.pandruvada@intel.com>,
        "pierre-louis.bossart@linux.intel.com" 
        <pierre-louis.bossart@linux.intel.com>,
        "Wang, Zhifeng" <zhifeng.wang@intel.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v2 1/3] media: pci: intel: ivsc: Add CSI submodule
Thread-Topic: [PATCH v2 1/3] media: pci: intel: ivsc: Add CSI submodule
Thread-Index: AQHZP1HqpZLwLlRt00ml9e7fRXtKOq7MO6AAgAG4EjCAACxFgIAAM1HwgADNUYCAA4fWgA==
Date:   Fri, 17 Feb 2023 05:52:38 +0000
Message-ID: <DM6PR11MB43164B18F9A1DBADA6B32BB08DA19@DM6PR11MB4316.namprd11.prod.outlook.com>
References: <20230213022347.2480307-1-wentong.wu@intel.com>
 <20230213034202.2926-1-hdanton@sina.com>
 <20230214083533.3410-1-hdanton@sina.com>
 <20230214235405.3587-1-hdanton@sina.com>
In-Reply-To: <20230214235405.3587-1-hdanton@sina.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?wN2yelMAN84y0y79ZxmGiSKPJjGjKq6pMBJE53vZUhAgqMDztCq7o01Q4+H2?=
 =?us-ascii?Q?R9UlwMEI/YFmVA1QAFDx+qD//vsc8MIonV6YzUk1N43s7PhpLMMfr0OiH1+C?=
 =?us-ascii?Q?c/C0cksP2aSmfXitA02Kvgh7iydOhsf+R0wyNCcEf+JrOxMmN9Npc4NCRMey?=
 =?us-ascii?Q?BRPJMsY5acTL48UT/VRw8YRIoX46K6LoTASR1NAKbIEVqTMtg52L4CUrnXYW?=
 =?us-ascii?Q?3caqT5s8Paqf2xmE6gQHHd5oPR7/E34T4IlnNic7gpeYGvex9JK278h5glCz?=
 =?us-ascii?Q?fyRBjazX0dICqhBnM3HGuKN/vvV43xgna9WQLM1saEnazXUvXt6Smbqowxxc?=
 =?us-ascii?Q?LEXM9rqQC/S7PEI1R0+MYWUFv/kgnWvHYPl6igbG5IY0noZ+AgtVmFMJBD9q?=
 =?us-ascii?Q?LDP1f9izkD91mR+na3DGqjQIzaHJjOq8yuXIsr4oUiaLvHfttqXgkYtl9NxE?=
 =?us-ascii?Q?qbrkF8XiWwoYLf5G1iLbVk3z4os+G7rZ4UctAGIshPseHzrRjYq4f5ZS3Ai+?=
 =?us-ascii?Q?zCGCluelhbQDojny8C2/dsbPQ0KlcIEHilVB2vj6Q9LEJGAVypbuOpiaDu3Q?=
 =?us-ascii?Q?i/qxQKeDz7fRNE8Vo04+WBbTgMJM+USHm+N1j9WiOch/7CsaWG6EZk9d+6QT?=
 =?us-ascii?Q?itJURVCfTZ6/MAXLx6v4nWrs721jF16lxU5lZ+2wDoXgnSssftUugoI54Iuz?=
 =?us-ascii?Q?PFpMrLOxnhIkTuMTpvJhNBaEgjHxjVGXxMY2aPfsjfTvG67X2ub0XCJdVJFI?=
 =?us-ascii?Q?ke7OW98jMMdWQ0mpWi6OuCCEHRw3l/5kZ5Zv6zRfBbGznUo+g0McjdYV6UjV?=
 =?us-ascii?Q?z6K9XIHX7XIV9Z6V0FiFEhLJ75GtQr7SARco8CZwMlyOmO1PyLfeIygjuD3C?=
 =?us-ascii?Q?/mMWeX6pQKdOaVXNNblG8HNlDkfgXwtNZZKZ297nhMNLazLOPXsBXFsYHOmv?=
 =?us-ascii?Q?2Um3/HSJr9duGBSK11dj76uy3Bn92Q2KZT3AuUyhS+NEtvxhhmROveDLJUS6?=
 =?us-ascii?Q?vuNjXWysT4y4RdvAbmt/cDlNqb5iJrkQJS9W/uCQVfI//PhPc+qF66zpyWa9?=
 =?us-ascii?Q?xmk3+V85EqwHVnf4zHaH/znyQqmQfZ5XRJjkyc7Aq7CwXSFIe7knmFVoGTLo?=
 =?us-ascii?Q?gFxJRYj5gNkNXKk5CX/vnWdAmZeOZR1qjPM+EF/b+5kBOVP/w778YyKTOCHN?=
 =?us-ascii?Q?Pe8lmRGQ/97ctx/s92v0Gx3uy2/TGtaWhLaCxh7N9qeFDDC9XgOMqF5owGow?=
 =?us-ascii?Q?96R5jSbz/jHOYGCMc4dzbLUWs9y8NBmITiu/ZFQj/x2ZJ1VT0iK4vBjz+Q/9?=
 =?us-ascii?Q?alr+P1hEiQ36QYPvui1ETVQhVyjjDKxyNaC62b+kWwG/lOz+mUoorzQZnoR/?=
 =?us-ascii?Q?qr1VoLfm2K55rNQKuO6tjF9QQ7umZ87VAECWHLPmBlGMcgprZP2i7Mw9ilMq?=
 =?us-ascii?Q?k1tbhAAxgLKDAMmdD1U8zy76p4mHazL+FJFtk6Bkp39JZI9CKdhuxwoNUTNt?=
 =?us-ascii?Q?v0jwR82UvJsM5rU6b702JquT/u1YkjSCInAAXPX2hR31zAcQBEEm7BrIePYM?=
 =?us-ascii?Q?EigaLuACuHKBLIMPesQ/ibsYQwiGaOR7LlFhs6mX?=
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: DM6PR11MB4316.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: fc41435d-1549-4d66-b6bf-08db10ab2d57
X-MS-Exchange-CrossTenant-originalarrivaltime: 17 Feb 2023 05:52:38.8607
 (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: giegfU2InEAFjg9ssl04owonPs0FVzpvwbOFEcKoWQ9ClGZWJ1SEK+c1wogTpp2nWuuD2HGISCYUeFDMpYvKUQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN9PR11MB5498
X-OriginatorOrg: intel.com
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


> -----Original Message-----
> From: Hillf Danton <hdanton@sina.com>
> Sent: Wednesday, February 15, 2023 7:54 AM
>=20
> On Tue, 14 Feb 2023 12:40:12 +0000 Wentong Wu <wentong.wu@intel.com>
> > > -----Original Message-----
> > > From: Hillf Danton <hdanton@sina.com>
> > > Sent: Tuesday, February 14, 2023 4:36 PM
> > >=3D20
> > > On Tue, 14 Feb 2023 06:25:35 +0000 Wentong Wu <wentong.wu@intel.com>
> > > >
> > > > This allows new command(e.g. 'get status' command to check current
> > > > firmware=3D3D
> > > >  status) to be downloaded to firmware for debugging purpose in
> > > > case no resp=3D3D onse for current command though I have never saw =
this
> happen.
> > > > =3D3D20
> > >=3D20
> > > Thanks for your specification.
> > >=3D20
> > > Another question, is it likely for the wakeup to come after reinit
> > >becaus=3D
> > e of for
> > > instance timeout on the waiter side?
> >
> > Thanks, first I want to clarify why we have timeout here, in case
> > firmware =3D stuck somehow or IVSC device is removed suddenly, calling
> > thread can't be w=3D akeup if wait forever here.
>=20
> Fair enough on the waiter side.
> >
> > And firmware gets high priority to handle command and response, also
> > there =3D is timeout mechanism inside firmware, I think there will be
> > some problem wi=3D th firmware if driver gets command response after 5s
> > which will be captured=3D  by driver code(if (csi->cmd_response.cmd_id
> > !=3D3D cmd->cmd_id)) but I have =3D never saw this happen.
>=20
> The problem with firmware could be emulated by directly skipping the wait=
 for
> completion and returning ETIMEDOUT, in order to see what will happen if
> wakeup comes later than timeout.

Thanks, but what do you mean "emulated"?=20