Re: [RFC v2 4/5] clk: per-user clock accounting for debug
From: Tomeu Vizoso
Date: Thu Jul 10 2014 - 06:52:09 EST
On 07/09/2014 10:01 PM, Tomasz Figa wrote:
Hi Tomeu, Rabin,
Please see my comments inline.
On 03.07.2014 16:38, Tomeu Vizoso wrote:
From: Rabin Vincent <rabin.vincent@xxxxxxxxxxxxxx>
When a clock has multiple users, the WARNING on imbalance of
enable/disable may not show the guilty party since although they may
have commited the error earlier, the warning is emitted later when some
other user, presumably innocent, disables the clock.
[snip]
diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
index 5f2aba9..d6a5e59 100644
--- a/drivers/clk/clk-devres.c
+++ b/drivers/clk/clk-devres.c
@@ -37,7 +37,8 @@ EXPORT_SYMBOL(devm_clk_provider_get);
struct clk *devm_clk_get(struct device *dev, const char *id)
{
- return clk_core_to_clk(devm_clk_provider_get(dev, id));
+ const char *dev_id = dev ? dev_name(dev) : NULL;
+ return clk_core_to_clk(devm_clk_provider_get(dev, id), dev_id, id);
Hmm, correct me if I'm missing something but you're just calling
devm_clk_provider() which guarantees calling of clk_provider_put() on
device removal, but what about the consumer struct being created here?
Shouldn't you rather call normal clk_provider_get() here, then create a
consumer struct for it and then wrap it up using devres, providing
appropriate release function?
You are totally right.
}
EXPORT_SYMBOL(devm_clk_get);
diff --git a/drivers/clk/clk-highbank.c b/drivers/clk/clk-highbank.c
index cc1bae1..4e38856 100644
--- a/drivers/clk/clk-highbank.c
+++ b/drivers/clk/clk-highbank.c
@@ -331,7 +331,7 @@ CLK_OF_DECLARE(hb_a9periph, "calxeda,hb-a9periph-clock", hb_a9periph_init);
static void __init hb_a9bus_init(struct device_node *node)
{
struct clk_core *clk = hb_clk_init(node, &a9bclk_ops);
- clk_prepare_enable(clk_core_to_clk(clk));
+ clk_prepare_enable(clk_core_to_clk(clk, node->full_name, NULL));
}
CLK_OF_DECLARE(hb_a9bus, "calxeda,hb-a9bus-clock", hb_a9bus_init);
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 644a824..b887c69 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -568,6 +568,28 @@ static int clk_disable_unused(void)
}
late_initcall_sync(clk_disable_unused);
+struct clk *clk_core_to_clk(struct clk_core *clk_core, const char *dev,
+ const char *con)
Name of this function suggests that this is just a simple conversion,
while it creates new object. I would suggest calling this
clk_create_consumer() or something along these lines.
Agreed, that sounds better.
+{
+ struct clk *clk;
+
+ clk = kzalloc(sizeof(*clk), GFP_KERNEL);
+ if (!clk)
+ return ERR_PTR(-ENOMEM);
[snip]
+static void clk_free_clk(struct clk *clk)
+{
+ kfree(clk);
+}
Any need for this one-liner? Seems to be used just once below.
Yeah, should probably remove it from this patch and only reintroduce it
later when it's actually needed.
+
void clk_put(struct clk *clk)
{
- __clk_put(clk_to_clk_core(clk));
+ clk_core_t *core = clk_to_clk_core(clk);
+
+ clk_free_clk(clk);
+ __clk_put(core);
}
EXPORT_SYMBOL(clk_put);
diff --git a/drivers/clk/qcom/mmcc-msm8960.c b/drivers/clk/qcom/mmcc-msm8960.c
index 28a5d30..47f21ea 100644
--- a/drivers/clk/qcom/mmcc-msm8960.c
+++ b/drivers/clk/qcom/mmcc-msm8960.c
@@ -470,7 +470,8 @@ static int pix_rdi_set_parent(struct clk_hw *hw, u8 index)
* needs to be on at what time.
*/
for (i = 0; i < num_parents; i++) {
- ret = clk_prepare_enable(clk_core_to_clk(clk_get_parent_by_index(clk, i)));
+ struct clk_core *parent = clk_get_parent_by_index(clk, i);
+ ret = clk_prepare_enable(clk_core_to_clk(parent, NULL, __clk_get_name(parent)));
Shouldn't this use clk_provider_*() instead? IMHO clk_core_to_clk() and
clk_to_clk_core() shouldn't be available to clock drivers, just the core
clock code. Consumers should operate on struct clks alone, clock drivers
should operate only on struct clk_cores and only the core code should be
responsible for necessary conversions.
Totally, this is already fixed in my local version.
if (ret)
goto err;
}
@@ -498,8 +499,10 @@ static int pix_rdi_set_parent(struct clk_hw *hw, u8 index)
udelay(1);
err:
- for (i--; i >= 0; i--)
- clk_disable_unprepare(clk_core_to_clk(clk_get_parent_by_index(clk, i)));
+ for (i--; i >= 0; i--) {
+ struct clk_core *parent = clk_get_parent_by_index(clk, i);
+ clk_disable_unprepare(clk_core_to_clk(parent, NULL, __clk_get_name(parent)));
Hmm. Memory leak? Every time this operation is called you create a
consumer struct for each parent two times.
Yes, fortunately this won't be needed as we'll have
clk_provider_disable_unprepare and friends.
+ }
return ret;
}
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index 5de44c1..550a691 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -1196,7 +1196,7 @@ static void __init sunxi_init_clocks(const char *clocks[], int nclocks)
struct clk_core *clk = clk_provider_get(NULL, clocks[i]);
if (!IS_ERR(clk))
- clk_prepare_enable(clk_core_to_clk(clk));
+ clk_prepare_enable(clk_core_to_clk(clk, NULL, clocks[i]));
Probably should use clk_provider_*()?
}
}
diff --git a/drivers/clk/tegra/clk.c b/drivers/clk/tegra/clk.c
index 385d101..2a03d47 100644
--- a/drivers/clk/tegra/clk.c
+++ b/drivers/clk/tegra/clk.c
@@ -228,7 +228,7 @@ void __init tegra_init_from_table(struct tegra_clk_init_table *tbl,
}
if (tbl->state)
- if (clk_prepare_enable(clk_core_to_clk(clk))) {
+ if (clk_prepare_enable(clk_core_to_clk(clk, NULL, __clk_get_name(clk)))) {
Ditto. And all similar cases below which I skipped due to lack of any
added value to this review.
pr_err("%s: Failed to enable %s\n", __func__,
__clk_get_name(clk));
WARN_ON(1);
[snip]
diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h
index 2c1ece9..9657fc8 100644
--- a/include/linux/clk-private.h
+++ b/include/linux/clk-private.h
@@ -57,6 +57,10 @@ struct clk_core {
struct clk {
struct clk_core *core;
+ unsigned int enable_count;
+ const char *dev_id;
+ const char *con_id;
+ void *last_disable;
Probably the same as for enables should be done for prepares.
Yes, I think it would be useful as well.
};
/*
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 87de32c..abfc31a 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -533,7 +533,8 @@ struct clk_core *clk_provider_get_sys(const char *dev_id, const char *con_id);
struct clk_core *clk_provider_get(struct device *dev, const char *con_id);
struct clk_core *devm_clk_provider_get(struct device *dev, const char *id);
-#define clk_core_to_clk(core) ((struct clk *)(core))
Btw. this should have been a static inline.
Agreed.
Thanks,
Tomeu
Best regards,
Tomasz
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/