[v3] firmware: qcom: scm: Fix incorrect of_node_put calls in scm_init

Message ID 1513345214-22835-1-git-send-email-lollivier@baylibre.com
State New
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Series
  • [v3] firmware: qcom: scm: Fix incorrect of_node_put calls in scm_init
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Commit Message

Loys Ollivier Dec. 15, 2017, 1:40 p.m.
When using other platform architectures, in the init of the qcom_scm
driver, of_node_put is called on /firmware if no qcom dt is found.
This results in a kernel error: Bad of_node_put() on /firmware.

These calls to of_node_put from the qcom_scm init are unnecessary as
of_find_matching_node and of_platform_populate are calling it
automatically.

Remove the calls to of_node_put() on fw_np.

Fixes: d0f6fa7ba2d6 ("firmware: qcom: scm: Convert SCM to platform driver")
Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Loys Ollivier <lollivier@baylibre.com>

---
 drivers/firmware/qcom_scm.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

-- 
2.7.4

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Comments

Bjorn Andersson Jan. 16, 2018, 4:45 p.m. | #1
On Fri 15 Dec 05:40 PST 2017, Loys Ollivier wrote:

> When using other platform architectures, in the init of the qcom_scm

> driver, of_node_put is called on /firmware if no qcom dt is found.

> This results in a kernel error: Bad of_node_put() on /firmware.

> 

> These calls to of_node_put from the qcom_scm init are unnecessary as

> of_find_matching_node and of_platform_populate are calling it

> automatically.

> 

> Remove the calls to of_node_put() on fw_np.

> 

> Fixes: d0f6fa7ba2d6 ("firmware: qcom: scm: Convert SCM to platform driver")

> Suggested-by: Stephen Boyd <sboyd@codeaurora.org>

> Signed-off-by: Loys Ollivier <lollivier@baylibre.com>


Hi Loys,

Your patch is correct! We are however removing all this logic from
qcom_scm_init() in v4.16.

See:
https://git.kernel.org/pub/scm/linux/kernel/git/agross/linux.git/commit/?h=for-next&id=3aa0582fdb824139630298880fbf78d4ac774d3c
https://git.kernel.org/pub/scm/linux/kernel/git/agross/linux.git/commit/?h=for-next&id=3aa0582fdb824139630298880fbf78d4ac774d3c

Regards,
Bjorn
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Sudeep Holla Jan. 16, 2018, 5:41 p.m. | #2
Hi Loys, Bjorn,

On Tue, Jan 16, 2018 at 08:45:49AM -0800, Bjorn Andersson wrote:
> On Fri 15 Dec 05:40 PST 2017, Loys Ollivier wrote:

> 

> > When using other platform architectures, in the init of the qcom_scm

> > driver, of_node_put is called on /firmware if no qcom dt is found.

> > This results in a kernel error: Bad of_node_put() on /firmware.

> > 

> > These calls to of_node_put from the qcom_scm init are unnecessary as

> > of_find_matching_node and of_platform_populate are calling it

> > automatically.

> > 

> > Remove the calls to of_node_put() on fw_np.

> > 

> > Fixes: d0f6fa7ba2d6 ("firmware: qcom: scm: Convert SCM to platform driver")

> > Suggested-by: Stephen Boyd <sboyd@codeaurora.org>

> > Signed-off-by: Loys Ollivier <lollivier@baylibre.com>

> 

> Hi Loys,

> 

> Your patch is correct! We are however removing all this logic from

> qcom_scm_init() in v4.16.

>


Unfortunately I seem to have carried the same issue to the new place.
I am fine if Loys wants to post the patch for the same. Let me know if you
want me to post, I have one handy(attached for the reference)

Regards,
Sudeep

-->8

From 7a563a6f793796339ba1b7a167a77f7353bdd58d Mon Sep 17 00:00:00 2001
From: Sudeep Holla <sudeep.holla@arm.com>

Date: Tue, 16 Jan 2018 17:17:28 +0000
Subject: [PATCH] of: platform: fix OF node refcount leak

We need to call of_node_put() for device nodes obtained with
of_find_node_by_path().

Reported-by: Loys Ollivier <lollivier@baylibre.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

---
 drivers/of/platform.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 6a01dab597c7..c00d81dfac0b 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -514,8 +514,10 @@ static int __init of_platform_default_populate_init(void)
 		of_platform_device_create(node, NULL, NULL);
 
 	node = of_find_node_by_path("/firmware");
-	if (node)
+	if (node) {
 		of_platform_populate(node, NULL, NULL, NULL);
+		of_node_put(node);
+	}
 
 	/* Populate everything else. */
 	of_platform_default_populate(NULL, NULL, NULL);
-- 
2.7.4

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Andy Gross Jan. 17, 2018, 11:47 p.m. | #3
On Tue, Jan 16, 2018 at 08:45:49AM -0800, Bjorn Andersson wrote:
> On Fri 15 Dec 05:40 PST 2017, Loys Ollivier wrote:

> 

> > When using other platform architectures, in the init of the qcom_scm

> > driver, of_node_put is called on /firmware if no qcom dt is found.

> > This results in a kernel error: Bad of_node_put() on /firmware.

> > 

> > These calls to of_node_put from the qcom_scm init are unnecessary as

> > of_find_matching_node and of_platform_populate are calling it

> > automatically.

> > 

> > Remove the calls to of_node_put() on fw_np.

> > 

> > Fixes: d0f6fa7ba2d6 ("firmware: qcom: scm: Convert SCM to platform driver")

> > Suggested-by: Stephen Boyd <sboyd@codeaurora.org>

> > Signed-off-by: Loys Ollivier <lollivier@baylibre.com>

> 

> Hi Loys,

> 

> Your patch is correct! We are however removing all this logic from

> qcom_scm_init() in v4.16.

> 

> See:

> https://git.kernel.org/pub/scm/linux/kernel/git/agross/linux.git/commit/?h=for-next&id=3aa0582fdb824139630298880fbf78d4ac774d3c

> https://git.kernel.org/pub/scm/linux/kernel/git/agross/linux.git/commit/?h=for-next&id=3aa0582fdb824139630298880fbf78d4ac774d3c



Yeah sorry for the delay in response.  I pulled in the second part of a separate
fix that removes all that code from the qcom_scm.  It made more sense to do it
automatically from the base code.

Andy
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Patch

diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index af4c75217ea6..f6d7b7cffe0c 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -632,17 +632,13 @@  static int __init qcom_scm_init(void)
 
 	np = of_find_matching_node(fw_np, qcom_scm_dt_match);
 
-	if (!np) {
-		of_node_put(fw_np);
+	if (!np)
 		return -ENODEV;
-	}
 
 	of_node_put(np);
 
 	ret = of_platform_populate(fw_np, qcom_scm_dt_match, NULL, NULL);
 
-	of_node_put(fw_np);
-
 	if (ret)
 		return ret;