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charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: VE1PR04MB6688.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: bb9ae2f4-c92c-4695-930a-08d915c218f6 X-MS-Exchange-CrossTenant-originalarrivaltime: 13 May 2021 03:49:23.4948 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: 54wdolHl1iMAnM7Rln2obQcQ2pAPIWVQqU4kVtu7Tojmoo/X+WER56QBUT2WWAFCN5xBdLYseI6O4x7mQtwdmw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR04MB6286 Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org On 5/12/21 22:15 Guenter Roeck wrote: > We can not assume that the situation is exactly the same for all drivers = and > use a core flag to indicate some driver specific state just to avoid a > driver-internal flag. >=20 > Either case, it looks like you are saying that the watchdog can be stoppe= d after > all, by disabling its clock. >=20 > > BTW, for i.mx2_wdt which watchdog can't be stop unless kernel enter > > into suspend, that seems like watchdog stop after suspend and clear > > WDOG_HW_RUNNING makes sense? > > >=20 > Yes, if you make it official and add a stop function which disables the > watchdog by stopping its clock. Then the driver should not set > WDOG_HW_RUNNING in the first place, and use the normal mechanisms to > start and stop the watchdog. > That would include starting the clock in the start function, and stopping= it in > the stop function. >=20 Sorry, watchdog can't be stopped by disabling clock. The only way to stop w= atchdog is SOC enter Deep Sleep Mode(suspend) and stopped by HW, so the suspend fl= ow looks like 'watchdog stop' which I though WDOG_HW_RUNNING makes sense.=20 Okay, I will use internal flag instead of WDOG_HW_RUNNING in v2, thanks.