@@ -454,11 +454,13 @@ static int i2c_device_remove(struct device *dev)
static int i2c_resume_early(struct device *dev)
{
struct i2c_client *client = i2c_verify_client(dev);
- struct i2c_adapter *adap = client->adapter;
int err;
+ if (!client)
+ return 0;
+
if (!pm_runtime_status_suspended(&client->dev)) {
- err = regulator_enable(adap->bus_regulator);
+ err = regulator_enable(client->adapter->bus_regulator);
if (err)
return err;
}
@@ -469,15 +471,17 @@ static int i2c_resume_early(struct device *dev)
static int i2c_suspend_late(struct device *dev)
{
struct i2c_client *client = i2c_verify_client(dev);
- struct i2c_adapter *adap = client->adapter;
int err;
+ if (!client)
+ return 0;
+
err = pm_generic_suspend_late(&client->dev);
if (err)
return err;
if (!pm_runtime_status_suspended(&client->dev))
- return regulator_disable(adap->bus_regulator);
+ return regulator_disable(client->adapter->bus_regulator);
return 0;
}
@@ -487,10 +491,12 @@ static int i2c_suspend_late(struct device *dev)
static int i2c_runtime_resume(struct device *dev)
{
struct i2c_client *client = i2c_verify_client(dev);
- struct i2c_adapter *adap = client->adapter;
int err;
- err = regulator_enable(adap->bus_regulator);
+ if (!client)
+ return 0;
+
+ err = regulator_enable(client->adapter->bus_regulator);
if (err)
return err;
@@ -500,14 +506,16 @@ static int i2c_runtime_resume(struct device *dev)
static int i2c_runtime_suspend(struct device *dev)
{
struct i2c_client *client = i2c_verify_client(dev);
- struct i2c_adapter *adap = client->adapter;
int err;
+ if (!client)
+ return 0;
+
err = pm_generic_runtime_suspend(&client->dev);
if (err)
return err;
- return regulator_disable(adap->bus_regulator);
+ return regulator_disable(client->adapter->bus_regulator);
}
#endif
Commit 6fe12cdbcfe3 ("i2c: core: support bus regulator controlling in adapter") added generic suspend and resume functions for i2c devices. Those functions unconditionally access an i2c_client structure assigned to the given i2c device. However, there exist i2c devices in the system without a valid i2c_client. Add the needed check before accessing the i2c_client. This fixes the following issue observed on Samsung Exynos4412-based Odroid U3 board: 8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000018 pgd = 2aed198a [00000018] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in: CPU: 1 PID: 1295 Comm: rtcwake Not tainted 5.7.0-rc6-02700-g4773d1324da6 #739 Hardware name: Samsung Exynos (Flattened Device Tree) PC is at i2c_suspend_late+0x20/0x48 LR is at dpm_run_callback+0xb4/0x3fc pc : [<c07b404c>] lr : [<c064b7cc>] psr: 20000053 ... Process rtcwake (pid: 1295, stack limit = 0x7f1885cf) Stack: (0xec8f3d70 to 0xec8f4000) ... [<c07b404c>] (i2c_suspend_late) from [<c064b7cc>] (dpm_run_callback+0xb4/0x3fc) [<c064b7cc>] (dpm_run_callback) from [<c064ce04>] (__device_suspend_late+0xcc/0x16c) [<c064ce04>] (__device_suspend_late) from [<c064f0b0>] (dpm_suspend_late+0x10c/0x568) [<c064f0b0>] (dpm_suspend_late) from [<c01996f0>] (suspend_devices_and_enter+0x31c/0xc70) [<c01996f0>] (suspend_devices_and_enter) from [<c019a43c>] (pm_suspend+0x3f8/0x480) [<c019a43c>] (pm_suspend) from [<c0198174>] (state_store+0x6c/0xc8) [<c0198174>] (state_store) from [<c035cf4c>] (kernfs_fop_write+0x10c/0x228) [<c035cf4c>] (kernfs_fop_write) from [<c02b94a4>] (__vfs_write+0x30/0x1d0) [<c02b94a4>] (__vfs_write) from [<c02bc444>] (vfs_write+0xa4/0x170) [<c02bc444>] (vfs_write) from [<c02bc690>] (ksys_write+0x60/0xd8) [<c02bc690>] (ksys_write) from [<c0100060>] (ret_fast_syscall+0x0/0x28) Exception stack(0xec8f3fa8 to 0xec8f3ff0) ... ---[ end trace a43afef431782f37 ]--- Fixes: 6fe12cdbcfe3 ("i2c: core: support bus regulator controlling in adapter") Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> --- This fixes suspend/resume issue observed on various board with linux-next from 20200521. --- drivers/i2c/i2c-core-base.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-)