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authorFabio Estevam <fabio.estevam@nxp.com>2016-10-22 15:20:56 +0300
committerShawn Guo <shawnguo@kernel.org>2016-10-24 10:13:02 +0300
commitf9d1f7a7ad919c93dfb708aae6e19d33c5437443 (patch)
tree75c9960e6763dd6173c20cf15198e5ee20b9dec4 /arch/arm
parenteef0b282bb586259d35548851cf6a4ce847bb804 (diff)
downloadlinux-f9d1f7a7ad919c93dfb708aae6e19d33c5437443.tar.xz
ARM: imx: gpc: Fix the imx_gpc_genpd_init() error path
If of_genpd_add_provider_onecell() fails the following kernel crash is observed on a kernel built with multi_v7_defconfig: [ 1.739301] [00000040] *pgd=00000000 [ 1.739310] Internal error: Oops: 5 [#1] SMP ARM [ 1.739319] Modules linked in: [ 1.739328] CPU: 1 PID: 95 Comm: kworker/1:4 Not tainted 4.8.0-11897-g6b5e09a #1 [ 1.739331] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) [ 1.739352] Workqueue: pm genpd_power_off_work_fn [ 1.739356] task: ee63d400 task.stack: ee70a000 [ 1.739365] PC is at mutex_lock+0xc/0x4c [ 1.739374] LR is at regulator_disable+0x2c/0x60 [ 1.739379] pc : [<c0bc0da0>] lr : [<c06e4b10>] psr: 60000013 [ 1.739379] sp : ee70beb0 ip : 10624dd3 fp : ee6e6280 [ 1.739382] r10: eefb0900 r9 : 00000000 r8 : c1309918 [ 1.739385] r7 : 00000000 r6 : 00000040 r5 : 00000000 r4 : 00000040 [ 1.739390] r3 : 0000004c r2 : 7fffd540 r1 : 000001e4 r0 : 00000040 Instead of returning of_genpd_add_provider_onecell() directly, we should check its return value and in the case of error we should unwind the previously taken actions, which in these case are: - Call imx6q_pm_pu_power_off() - Set imx6q_pu_domain.reg back to NULL Setting imx6q_pu_domain.reg to NULL in the error case is important as it will prevent further operations in the pu_reg regulator. This kernel crash is not observed with imx_v6_v7_defconfig because it selects GPU and VPU drivers, which are consumers of the GPC block and thus change the refcount of the pu_reg regulator. Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/mach-imx/gpc.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/arm/mach-imx/gpc.c b/arch/arm/mach-imx/gpc.c
index d0463e9d8a08..b54db47f6f32 100644
--- a/arch/arm/mach-imx/gpc.c
+++ b/arch/arm/mach-imx/gpc.c
@@ -408,7 +408,7 @@ static struct genpd_onecell_data imx_gpc_onecell_data = {
static int imx_gpc_genpd_init(struct device *dev, struct regulator *pu_reg)
{
struct clk *clk;
- int i;
+ int i, ret;
imx6q_pu_domain.reg = pu_reg;
@@ -432,12 +432,20 @@ static int imx_gpc_genpd_init(struct device *dev, struct regulator *pu_reg)
for (i = 0; i < ARRAY_SIZE(imx_gpc_domains); i++)
pm_genpd_init(imx_gpc_domains[i], NULL, false);
- return of_genpd_add_provider_onecell(dev->of_node,
+
+ ret = of_genpd_add_provider_onecell(dev->of_node,
&imx_gpc_onecell_data);
+ if (ret)
+ goto power_off;
+
+ return 0;
+power_off:
+ imx6q_pm_pu_power_off(&imx6q_pu_domain.base);
clk_err:
while (i--)
clk_put(imx6q_pu_domain.clk[i]);
+ imx6q_pu_domain.reg = NULL;
return -EINVAL;
}