| Message ID | 1516702990-25564-1-git-send-email-ulf.hansson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | PM / Domains: Fixup domain-idle-states OF parsing | expand |
Hi Ulf, Thanks for the fix. The allocation is more than what is needed and this will fix that. On Tue, Jan 23 2018 at 10:23 +0000, Ulf Hansson wrote: >but also makes of_genpd_parse_idle_states() to return the wrong number of >allocated elements to the caller. > How is this happening? > >Fixes: b539cc82d493 ("PM / Domains: Ignore domain-idle-states that are not compatible") >Cc: Lina Iyer <ilina@codeaurora.org> >Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> >--- > drivers/base/power/domain.c | 76 +++++++++++++++++++++++++++------------------ > 1 file changed, 45 insertions(+), 31 deletions(-) > >- /* Loop over the phandles until all the requested entry is found */ >- of_for_each_phandle(&it, err, dn, "domain-idle-states", NULL, 0) { >- np = it.node; >- match_id = of_match_node(idle_state_match, np); >- if (!match_id) >- continue; >- ret = genpd_parse_state(&st[i++], np); This increments only if the state node matches the compatible. >- if (ret) { >- pr_err >- ("Parsing idle state node %pOF failed with err %d\n", >- np, ret); >- of_node_put(np); >- kfree(st); >- return ret; >- } >+ ret = genpd_iterate_idle_states(dn, st); >+ if (ret <= 0) { >+ kfree(st); >+ return ret < 0 ? ret : -EINVAL; > } > >- *n = i; Returns the count of matched state nodes. What am I missing? -- Lina
On 23 January 2018 at 17:12, Lina Iyer <ilina@codeaurora.org> wrote: > Hi Ulf, > > Thanks for the fix. The allocation is more than what is needed and this > will fix that. > > On Tue, Jan 23 2018 at 10:23 +0000, Ulf Hansson wrote: >> >> but also makes of_genpd_parse_idle_states() to return the wrong number of >> allocated elements to the caller. >> > How is this happening? > >> >> Fixes: b539cc82d493 ("PM / Domains: Ignore domain-idle-states that are not >> compatible") >> Cc: Lina Iyer <ilina@codeaurora.org> >> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> >> --- >> drivers/base/power/domain.c | 76 >> +++++++++++++++++++++++++++------------------ >> 1 file changed, 45 insertions(+), 31 deletions(-) >> >> - /* Loop over the phandles until all the requested entry is found >> */ >> - of_for_each_phandle(&it, err, dn, "domain-idle-states", NULL, 0) { >> - np = it.node; >> - match_id = of_match_node(idle_state_match, np); >> - if (!match_id) >> - continue; >> - ret = genpd_parse_state(&st[i++], np); > > This increments only if the state node matches the compatible. > >> - if (ret) { >> - pr_err >> - ("Parsing idle state node %pOF failed with err >> %d\n", >> - np, ret); >> - of_node_put(np); >> - kfree(st); >> - return ret; >> - } >> + ret = genpd_iterate_idle_states(dn, st); >> + if (ret <= 0) { >> + kfree(st); >> + return ret < 0 ? ret : -EINVAL; >> } >> >> - *n = i; > > Returns the count of matched state nodes. > > What am I missing? You are correct, there is nothing wrong here in regards to counting and returning the number a *valid* idle states nodes. However, I was referring in the changelog to the number of elements that has been *allocated*. Obviously the number of elements allocated will not match the numbers of valid idle state nodes, in case there is one of more nodes not being compatible. This is probably not an issue, so let me re-phrase the change log, to make this more clear. Thanks for reviewing! Kind regards Uffe
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 528b241..1ea0e25 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -2290,6 +2290,38 @@ static int genpd_parse_state(struct genpd_power_state *genpd_state, return 0; } +static int genpd_iterate_idle_states(struct device_node *dn, + struct genpd_power_state *states) +{ + int ret; + struct of_phandle_iterator it; + struct device_node *np; + int i = 0; + + ret = of_count_phandle_with_args(dn, "domain-idle-states", NULL); + if (ret <= 0) + return ret; + + /* Loop over the phandles until all the requested entry is found */ + of_for_each_phandle(&it, ret, dn, "domain-idle-states", NULL, 0) { + np = it.node; + if (!of_match_node(idle_state_match, np)) + continue; + if (states) { + ret = genpd_parse_state(&states[i], np); + if (ret) { + pr_err("Parsing idle state node %pOF failed with err %d\n", + np, ret); + of_node_put(np); + return ret; + } + } + i++; + } + + return i; +} + /** * of_genpd_parse_idle_states: Return array of idle states for the genpd. * @@ -2299,49 +2331,31 @@ static int genpd_parse_state(struct genpd_power_state *genpd_state, * * Returns the device states parsed from the OF node. The memory for the states * is allocated by this function and is the responsibility of the caller to - * free the memory after use. + * free the memory after use. If no domain idle states is found it returns + * -EINVAL and in case of errors, a negative error code. */ int of_genpd_parse_idle_states(struct device_node *dn, struct genpd_power_state **states, int *n) { struct genpd_power_state *st; - struct device_node *np; - int i = 0; - int err, ret; - int count; - struct of_phandle_iterator it; - const struct of_device_id *match_id; + int ret; - count = of_count_phandle_with_args(dn, "domain-idle-states", NULL); - if (count <= 0) - return -EINVAL; + ret = genpd_iterate_idle_states(dn, NULL); + if (ret <= 0) + return ret < 0 ? ret : -EINVAL; - st = kcalloc(count, sizeof(*st), GFP_KERNEL); + st = kcalloc(ret, sizeof(*st), GFP_KERNEL); if (!st) return -ENOMEM; - /* Loop over the phandles until all the requested entry is found */ - of_for_each_phandle(&it, err, dn, "domain-idle-states", NULL, 0) { - np = it.node; - match_id = of_match_node(idle_state_match, np); - if (!match_id) - continue; - ret = genpd_parse_state(&st[i++], np); - if (ret) { - pr_err - ("Parsing idle state node %pOF failed with err %d\n", - np, ret); - of_node_put(np); - kfree(st); - return ret; - } + ret = genpd_iterate_idle_states(dn, st); + if (ret <= 0) { + kfree(st); + return ret < 0 ? ret : -EINVAL; } - *n = i; - if (!i) - kfree(st); - else - *states = st; + *states = st; + *n = ret; return 0; }
The commit b539cc82d493 ("PM / Domains: Ignore domain-idle-states that are not compatible"), made it possible to ignore non-compatible domain-idle-states OF nodes. However, in case that happens while doing the OF parsing, the number of elements in the allocated array would exceed the numbers actually needed. Moreover, the behaviour may not only cause a bigger allocation than needed, but also makes of_genpd_parse_idle_states() to return the wrong number of allocated elements to the caller. Fix this by pre-iterating the genpd OF node and counting the number of compatible domain-idle-states nodes, before doing the allocation. While doing this, it makes sense to rework the code a bit to avoid open coding, of parts responsible for OF node iteration. Let's also take the opportunity to clarify the function header for of_genpd_parse_idle_states(), about what is being returned in case of errors. Fixes: b539cc82d493 ("PM / Domains: Ignore domain-idle-states that are not compatible") Cc: Lina Iyer <ilina@codeaurora.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- drivers/base/power/domain.c | 76 +++++++++++++++++++++++++++------------------ 1 file changed, 45 insertions(+), 31 deletions(-) -- 2.7.4