[PATCH] ARM: OMAP3+: Fix kernel panic on boot

[PATCH] ARM: OMAP3+: Fix kernel panic on boot

[Jon Hunter]

Commit 8a6aaa3 (mfd: twl-core: Collect global variables behind one
private structure (global)) removed the variable "inuse" that is used
to determine if the device has been initialised and now use the
twl_priv structure instead. This is causing the kernel to panic on
OMAP3+ devices using the twl driver, because we try to access the
twl_priv->ready member before checking if twl_priv is initialised. Fix
this and move this test to the beginning of the twl_i2c_read/write
function because twl_get_last_module() also uses the twl_priv structure.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
 drivers/mfd/twl-core.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c
index 557f9ee..89ab4d9 100644
--- a/drivers/mfd/twl-core.c
+++ b/drivers/mfd/twl-core.c
@@ -316,12 +316,12 @@ int twl_i2c_write(u8 mod_no, u8 *value, u8 reg, unsigned num_bytes)
 	int sid;
 	struct twl_client *twl;
 
-	if (unlikely(mod_no >= twl_get_last_module())) {
-		pr_err("%s: invalid module number %d\n", DRIVER_NAME, mod_no);
+	if (unlikely(!twl_priv || !twl_priv->ready)) {
+		pr_err("%s: not initialized\n", DRIVER_NAME);
 		return -EPERM;
 	}
-	if (unlikely(!twl_priv->ready)) {
-		pr_err("%s: not initialized\n", DRIVER_NAME);
+	if (unlikely(mod_no >= twl_get_last_module())) {
+		pr_err("%s: invalid module number %d\n", DRIVER_NAME, mod_no);
 		return -EPERM;
 	}
 
@@ -355,12 +355,12 @@ int twl_i2c_read(u8 mod_no, u8 *value, u8 reg, unsigned num_bytes)
 	int sid;
 	struct twl_client *twl;
 
-	if (unlikely(mod_no >= twl_get_last_module())) {
-		pr_err("%s: invalid module number %d\n", DRIVER_NAME, mod_no);
+	if (unlikely(!twl_priv || !twl_priv->ready)) {
+		pr_err("%s: not initialized\n", DRIVER_NAME);
 		return -EPERM;
 	}
-	if (unlikely(!twl_priv->ready)) {
-		pr_err("%s: not initialized\n", DRIVER_NAME);
+	if (unlikely(mod_no >= twl_get_last_module())) {
+		pr_err("%s: invalid module number %d\n", DRIVER_NAME, mod_no);
 		return -EPERM;
 	}
 
-- 
1.7.10.4

[PATCH] ARM: OMAP3+: Fix kernel panic on boot

[Samuel Ortiz]

Hi Jon,

On Mon, Feb 11, 2013 at 02:26:19PM -0600, Jon Hunter wrote:
> Commit 8a6aaa3 (mfd: twl-core: Collect global variables behind one
> private structure (global)) removed the variable "inuse" that is used
> to determine if the device has been initialised and now use the
> twl_priv structure instead. This is causing the kernel to panic on
> OMAP3+ devices using the twl driver, because we try to access the
> twl_priv->ready member before checking if twl_priv is initialised. Fix
> this and move this test to the beginning of the twl_i2c_read/write
> function because twl_get_last_module() also uses the twl_priv structure.
> 
> Signed-off-by: Jon Hunter <jon-hunter@ti.com>
> Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
> ---
>  drivers/mfd/twl-core.c |   16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
Patch applied, thanks.
I fixed the subject as it's codewise not ARM or OMAP3 related, but rather mfd
and twl-core.

Cheers,
Samuel.

-- 
Intel Open Source Technology Centre
http://oss.intel.com/

[PATCH] ARM: OMAP3+: Fix kernel panic on boot

[Jon Hunter]

On 02/12/2013 04:07 AM, Samuel Ortiz wrote:
> Hi Jon,
> 
> On Mon, Feb 11, 2013 at 02:26:19PM -0600, Jon Hunter wrote:
>> Commit 8a6aaa3 (mfd: twl-core: Collect global variables behind one
>> private structure (global)) removed the variable "inuse" that is used
>> to determine if the device has been initialised and now use the
>> twl_priv structure instead. This is causing the kernel to panic on
>> OMAP3+ devices using the twl driver, because we try to access the
>> twl_priv->ready member before checking if twl_priv is initialised. Fix
>> this and move this test to the beginning of the twl_i2c_read/write
>> function because twl_get_last_module() also uses the twl_priv structure.
>>
>> Signed-off-by: Jon Hunter <jon-hunter@ti.com>
>> Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
>> ---
>>  drivers/mfd/twl-core.c |   16 ++++++++--------
>>  1 file changed, 8 insertions(+), 8 deletions(-)
> Patch applied, thanks.
> I fixed the subject as it's codewise not ARM or OMAP3 related, but rather mfd
> and twl-core.

Good point! Thanks Jon