Hi Nicolas, On 27/10/20 1:19, Nicolas Boichat wrote: > Hi Enric, > > On Mon, Oct 26, 2020 at 11:17 PM Enric Balletbo i Serra > <enric.balle...@collabora.com> wrote: >> >> Hi Nicolas, >> >> Many thanks for looking at this. > > Thanks to you ,-) > > [snip] >>>> + if (id >= scpsys->soc_data->num_domains) { >>>> + dev_err_probe(scpsys->dev, -EINVAL, "%pOFn: invalid domain >>>> id %d\n", node, id); >>>> + return -EINVAL; >>>> + } >>>> + >>>> + domain_data = &scpsys->soc_data->domains[id]; >>>> + if (!domain_data) { >>> >>> Is that even possible at all? I mean, even if >>> scpsys->soc_data->domains is NULL, as long as id != 0, this will no >>> happen. >>> >> >> I think could happen with a bad DT definition. I.e if for the definition of >> the >> MT8173 domains you use a wrong value for the reg property, a value that is >> not >> present in the SoC data. It is unlikely if you use the defines but could >> happen >> if you hardcore the value. We cannot check this with the DT json-schema. > > I wasn't clear in my explanation, and looking further there is more > that looks wrong. > > This expression &scpsys->soc_data->domains[id] is a pointer to element > "id" of the array domains. So if you convert to integer arithmetic, > it'll be something like `(long)scpsys->soc_data->domains + > (sizeof(struct generic_pm_domain *)) * id`. The only way this can be > NULL is if scpsys->soc_data->domains pointer is NULL, which, actually, > can't really happen as it's the 5th element of a struct scpsys > structure `(long)scpsys->soc_data + offset_of(domains, struct scpsys) > + (sizeof(struct generic_pm_domain *)) * id`. > > I think what you mean is either: > domain_data = &scpsys->soc_data->domains[id]; > if (!*domain_data) > [but then domain_data type should be `struct generic_pm_domain **`?
I think you're confusing the field `struct generic_pm_domain *domains[]`from the `struct scpsys` with `const struct scpsys_domain_data *domains` from `struct scpsys_soc_data`. My bad they have the same name, I should probably rename the second one as domain_info or domain_data to avoid that confusion. diff --git a/drivers/soc/mediatek/mtk-pm-domains.h b/drivers/soc/mediatek/mtk-pm-domains.h index 7c8efcb3cef2..6ff095db8a27 100644 --- a/drivers/soc/mediatek/mtk-pm-domains.h +++ b/drivers/soc/mediatek/mtk-pm-domains.h @@ -56,7 +56,7 @@ struct scpsys_domain_data { }; struct scpsys_soc_data { - const struct scpsys_domain_data *domains; + const struct scpsys_domain_data *domain_data; int num_domains; int pwr_sta_offs; int pwr_sta2nd_offs; --- struct scpsys { ... const struct scpsys_soc_data *soc_data; ... struct generic_pm_domain *domains[]; } domain_data = &scpsys->soc_data->domain_data[id]; if (!domain_data) Thanks, Enric > Does your code compile with warnings enabled?] > or: > domain_data = scpsys->soc_data->domains[id]; > if (!domain_data) > [then the test makes sense] > > [snip] >