On 01-09-20, 15:15, Rajendra Nayak wrote:
On 9/1/2020 2:08 PM, Viresh Kumar wrote:
On 01-09-20, 13:01, Rajendra Nayak wrote:
So FWIU, dpu_unbind() gets called even when dpu_bind() fails for some reason.
Ahh, I see.
I tried to address that earlier [1] which I realized did not land.
I don't think that patch was required, as you can call dev_pm_opp_put_clkname() multiple times and it will return without any errors/crash.
We did see a crash (Sai had reported it), perhaps with dsi [1] and not this driver. But it was the same scenario that was possible here as well, which is dev_pm_opp_put_clkname() getting called without dev_pm_opp_set_clkname() being done. I think we ended up passing a NULL as opp_table in that case and the function tries de-referencing it.
Heh, yeah I did miss that stupid thing :(
But with these changes it will be even more broken unless we identify if we failed dpu_bind() before adding the OPP table, while adding it, or all went well with opps and handle things accordingly in dpu_unbind.
Maybe not as dev_pm_opp_of_remove_table() can be called multiple times as well without any errors or crash.
Can it be called without the driver ever doing a dev_pm_opp_of_add_table()?
Yes, as we will fail to find the OPP device in that case with -ENODEV and so won't even print a warning.
Also if the OPP table was previously added as a response to dev_pm_opp_set_clkname(), then we won't free it as well. So yes, it should work just fine.