Hi Sakari, On Mon, Oct 31, 2022 at 2:25 PM Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> wrote: > > Hi Prabhakar, > > On Thu, Oct 27, 2022 at 06:37:58PM +0000, Sakari Ailus wrote: > > Hi Prabhakar, > > > > On Thu, Oct 27, 2022 at 05:32:07PM +0100, Lad, Prabhakar wrote: > > > Hi Sakari, > > > > > > On Thu, Oct 27, 2022 at 1:47 PM Sakari Ailus > > > <sakari.ailus@xxxxxxxxxxxxxxx> wrote: > > > > > > > > Hi Prabhakar, > > > > > > > > On Thu, Oct 27, 2022 at 01:01:52PM +0100, Lad, Prabhakar wrote: > > > > > Hi Sakari, > > > > > > > > > > On Thu, Oct 27, 2022 at 12:20 PM Sakari Ailus > > > > > <sakari.ailus@xxxxxxxxxxxxxxx> wrote: > > > > > > > > > > > > Hi Prabhakar, > > > > > > > > > > > > One more comment. > > > > > > > > > > > > On Fri, Oct 14, 2022 at 07:34:56PM +0100, Prabhakar wrote: > > > > > > > @@ -1209,12 +1190,16 @@ static int ov5645_probe(struct i2c_client *client) > > > > > > > > > > > > > > dev_info(dev, "OV5645 detected at address 0x%02x\n", client->addr); > > > > > > > > > > > > > > + pm_runtime_set_active(dev); > > > > > > > + pm_runtime_get_noresume(dev); > > > > > > > + pm_runtime_enable(dev); > > > > > > > > > > > > You won't gain anything by eanbling runtime PM here. Just move it to the > > > > > > end of the function before the rest of the calls. Error handling becomes > > > > > > more simple. > > > > > > > > > > > If I move the above calls below I get the below warning: > > > > > > > > > > [ 2.633386] ov5645 0-003c: Runtime PM usage count underflow! > > > > > > > > > > This is because of the last patch which moves ov5645_entity_init_cfg() > > > > > before registering the subdev. ov5645_entity_init_cfg() calls s_ctrl > > > > > due to which we are seeing the above message. Please let me know how > > > > > to proceed on this. > > > > > > > > Ah. Yes, this is a problem with the usage pattern of > > > > pm_runtime_get_if_in_use(). But please don't change that. > > > > > > > > You can still move enabling runtime PM later in the function. > > > > > > > Agreed, the final version looks like below: > > > > > > pm_runtime_set_active(dev); > > > pm_runtime_get_noresume(dev); > > > > > > > You'll have to enable runtime PM here, before pm_runtime_get_if_in_use() > > gets called. > > > > I'll see if it could be made to work in a sensible way when runtime PM > > isn't enabled yet. > > There are various ways how runtime PM interface functions generally work, > and generally return an error when runtime PM is disabled. Incrementing the > usage_count when runtime PM is disabled would make > pm_runtime_get_if_in_use() very special and not match what the rest would > do. Therefore I think it's best to keep this in the driver. After all, mo > other driver needs this in the media tree, which is the major user of the > function. > Thank you for digging deep into this. I'll keep it as is and send a v3. Cheers, Prabhakar
