[PATCH v4 0/5] platform/chrome: cros_ec: miscellaneous cleanups

[PATCH v4 0/5] platform/chrome: cros_ec: miscellaneous cleanups

[Tzung-Bi Shih]

The 1st patch fixes unhandled undos in error handling path.

The rest of patches cleans drivers/platform/chrome/cros_ec.c.

Changes from v3:
(https://patchwork.kernel.org/project/chrome-platform/cover/20220209095703.517608-1-tzungbi@google.com/)
- Drop "platform/chrome: cros_ec: don't initialize `err` in cros_ec_register()".
- Rename the 3rd patch's title.

Changes from v2:
(https://patchwork.kernel.org/project/chrome-platform/cover/20220209045035.380615-1-tzungbi@google.com/)
- Fix review comments in 1st and 2nd patch.

Changes from v1:
(https://lore.kernel.org/lkml/20220125101527.1812887-1-tzungbi@google.com/T/#u)
- Use imperative mood in commit messages.
- Use IS_ERR_OR_NULL() in 1st patch.

Tzung-Bi Shih (5):
  platform/chrome: cros_ec: fix error handling in cros_ec_register()
  platform/chrome: cros_ec: remove unused variable `was_wake_device`
  platform/chrome: cros_ec: initialize `wake_enabled` in
    cros_ec_register()
  platform/chrome: cros_ec: sort header inclusion alphabetically
  platform/chrome: cros_ec: append newline to all logs

 drivers/platform/chrome/cros_ec.c           | 35 +++++++++++----------
 include/linux/platform_data/cros_ec_proto.h |  3 --
 2 files changed, 19 insertions(+), 19 deletions(-)

-- 
2.35.1.265.g69c8d7142f-goog

[PATCH v4 1/5] platform/chrome: cros_ec: fix error handling in cros_ec_register()

[Tzung-Bi Shih]

Fix cros_ec_register() to unregister platform devices if
blocking_notifier_chain_register() fails.

Also use the single exit path to handle the platform device
unregistration.

Fixes: 42cd0ab476e2 ("platform/chrome: cros_ec: Query EC protocol version if EC transitions between RO/RW")
Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
---
Changes from v3:
(https://patchwork.kernel.org/project/chrome-platform/patch/20220209095703.517608-2-tzungbi@google.com/)
- Simplify by initializing the variables at the beginning.

Changes from v2:
(https://patchwork.kernel.org/project/chrome-platform/patch/20220209045035.380615-2-tzungbi@google.com/)
- Fix grammar error in commit message.
- Change the code that don't rely on zeroed memory.
- Remove unnecessary `if` checks before calling platform_device_unregister().

Changes from v1:
(https://lore.kernel.org/lkml/20220125101527.1812887-1-tzungbi@google.com/T/#u)
- Use imperative mood in commit message.
- Use IS_ERR_OR_NULL() in 1st patch.

 drivers/platform/chrome/cros_ec.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
index fc5aa1525d13..ff2a24b0c611 100644
--- a/drivers/platform/chrome/cros_ec.c
+++ b/drivers/platform/chrome/cros_ec.c
@@ -189,6 +189,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 	ec_dev->max_request = sizeof(struct ec_params_hello);
 	ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
 	ec_dev->max_passthru = 0;
+	ec_dev->ec = NULL;
+	ec_dev->pd = NULL;
 
 	ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
 	if (!ec_dev->din)
@@ -245,18 +247,16 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 		if (IS_ERR(ec_dev->pd)) {
 			dev_err(ec_dev->dev,
 				"Failed to create CrOS PD platform device\n");
-			platform_device_unregister(ec_dev->ec);
-			return PTR_ERR(ec_dev->pd);
+			err = PTR_ERR(ec_dev->pd);
+			goto exit;
 		}
 	}
 
 	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
 		err = devm_of_platform_populate(dev);
 		if (err) {
-			platform_device_unregister(ec_dev->pd);
-			platform_device_unregister(ec_dev->ec);
 			dev_err(dev, "Failed to register sub-devices\n");
-			return err;
+			goto exit;
 		}
 	}
 
@@ -278,7 +278,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 		err = blocking_notifier_chain_register(&ec_dev->event_notifier,
 						      &ec_dev->notifier_ready);
 		if (err)
-			return err;
+			goto exit;
 	}
 
 	dev_info(dev, "Chrome EC device registered\n");
@@ -291,6 +291,10 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 		cros_ec_irq_thread(0, ec_dev);
 
 	return 0;
+exit:
+	platform_device_unregister(ec_dev->ec);
+	platform_device_unregister(ec_dev->pd);
+	return err;
 }
 EXPORT_SYMBOL(cros_ec_register);
 
-- 
2.35.1.265.g69c8d7142f-goog

[PATCH v4 2/5] platform/chrome: cros_ec: remove unused variable `was_wake_device`

[Tzung-Bi Shih]

Reviewed-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
---
No changes from v3.

Changes from v2:
(https://patchwork.kernel.org/project/chrome-platform/patch/20220209045035.380615-3-tzungbi@google.com/)
- Add pmalani's R-b tag.
- Remove redundant commit message.

Changes from v1:
(https://lore.kernel.org/lkml/20220125101527.1812887-1-tzungbi@google.com/T/#u)
- Use imperative mood in commit message.

 drivers/platform/chrome/cros_ec.c           | 1 -
 include/linux/platform_data/cros_ec_proto.h | 3 ---
 2 files changed, 4 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
index ff2a24b0c611..25cd8df6e7b0 100644
--- a/drivers/platform/chrome/cros_ec.c
+++ b/drivers/platform/chrome/cros_ec.c
@@ -344,7 +344,6 @@ int cros_ec_suspend(struct cros_ec_device *ec_dev)
 		ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
 
 	disable_irq(ec_dev->irq);
-	ec_dev->was_wake_device = ec_dev->wake_enabled;
 	ec_dev->suspended = true;
 
 	return 0;
diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h
index df3c78c92ca2..c65971ec90ea 100644
--- a/include/linux/platform_data/cros_ec_proto.h
+++ b/include/linux/platform_data/cros_ec_proto.h
@@ -76,8 +76,6 @@ struct cros_ec_command {
  * struct cros_ec_device - Information about a ChromeOS EC device.
  * @phys_name: Name of physical comms layer (e.g. 'i2c-4').
  * @dev: Device pointer for physical comms device
- * @was_wake_device: True if this device was set to wake the system from
- *                   sleep at the last suspend.
  * @cros_class: The class structure for this device.
  * @cmd_readmem: Direct read of the EC memory-mapped region, if supported.
  *     @offset: Is within EC_LPC_ADDR_MEMMAP region.
@@ -137,7 +135,6 @@ struct cros_ec_device {
 	/* These are used by other drivers that want to talk to the EC */
 	const char *phys_name;
 	struct device *dev;
-	bool was_wake_device;
 	struct class *cros_class;
 	int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
 			   unsigned int bytes, void *dest);
-- 
2.35.1.265.g69c8d7142f-goog

[PATCH v4 3/5] platform/chrome: cros_ec: initialize `wake_enabled` in cros_ec_register()

[Tzung-Bi Shih]

`wake_enabled` indicates cros_ec_resume() needs to call
disable_irq_wake() to undo enable_irq_wake() in cros_ec_suspend().

Initialize `wake_enabled` in cros_ec_register() and determine the flag
in cros_ec_suspend() instead of reset-after-used in cros_ec_resume().

Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
---
Changes from v3:
(https://patchwork.kernel.org/project/chrome-platform/patch/20220209095703.517608-4-tzungbi@google.com/)
- Change the patch title.
- Simplify by initializing wake_enabled in cros_ec_register().

No changes from v2.

Changes from v1:
(https://lore.kernel.org/lkml/20220125101527.1812887-1-tzungbi@google.com/T/#u)
- Use imperative mood in commit message.

 drivers/platform/chrome/cros_ec.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
index 25cd8df6e7b0..b6604a9ab315 100644
--- a/drivers/platform/chrome/cros_ec.c
+++ b/drivers/platform/chrome/cros_ec.c
@@ -191,6 +191,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 	ec_dev->max_passthru = 0;
 	ec_dev->ec = NULL;
 	ec_dev->pd = NULL;
+	ec_dev->wake_enabled = false;
 
 	ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
 	if (!ec_dev->din)
@@ -383,10 +384,9 @@ int cros_ec_resume(struct cros_ec_device *ec_dev)
 		dev_dbg(ec_dev->dev, "Error %d sending resume event to ec",
 			ret);
 
-	if (ec_dev->wake_enabled) {
+	if (ec_dev->wake_enabled)
 		disable_irq_wake(ec_dev->irq);
-		ec_dev->wake_enabled = 0;
-	}
+
 	/*
 	 * Let the mfd devices know about events that occur during
 	 * suspend. This way the clients know what to do with them.
-- 
2.35.1.265.g69c8d7142f-goog

[PATCH v4 4/5] platform/chrome: cros_ec: sort header inclusion alphabetically

[Tzung-Bi Shih]

Sort header inclusion alphabetically.

Reviewed-by: Guenter Roeck <groeck@google.com>
Reviewed-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
---
Changes from v3:
(https://patchwork.kernel.org/project/chrome-platform/patch/20220209095703.517608-6-tzungbi@google.com/)
- Add R-b tags.

No changes from v2.

Changes from v1:
(https://lore.kernel.org/lkml/20220125101527.1812887-1-tzungbi@google.com/T/#u)
- Use imperative mood in commit message.

 drivers/platform/chrome/cros_ec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
index b6604a9ab315..a3921fe5813a 100644
--- a/drivers/platform/chrome/cros_ec.c
+++ b/drivers/platform/chrome/cros_ec.c
@@ -9,12 +9,12 @@
  * battery charging and regulator control, firmware update.
  */
 
-#include <linux/of_platform.h>
 #include <linux/interrupt.h>
-#include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/of_platform.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
+#include <linux/slab.h>
 #include <linux/suspend.h>
 
 #include "cros_ec.h"
-- 
2.35.1.265.g69c8d7142f-goog

[PATCH v4 5/5] platform/chrome: cros_ec: append newline to all logs

[Tzung-Bi Shih]

To be consistent, append newline ("\n") to all logs.

Reviewed-by: Guenter Roeck <groeck@google.com>
Reviewed-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
---
Changes from v3:
(https://patchwork.kernel.org/project/chrome-platform/patch/20220209095703.517608-7-tzungbi@google.com/)
- Add R-b tags.

No changes from v2.

Changes from v1:
(https://lore.kernel.org/lkml/20220125101527.1812887-1-tzungbi@google.com/T/#u)
- Use imperative mood in commit message.

 drivers/platform/chrome/cros_ec.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
index a3921fe5813a..a45bbc589928 100644
--- a/drivers/platform/chrome/cros_ec.c
+++ b/drivers/platform/chrome/cros_ec.c
@@ -216,7 +216,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 						"chromeos-ec", ec_dev);
 		if (err) {
-			dev_err(dev, "Failed to request IRQ %d: %d",
+			dev_err(dev, "Failed to request IRQ %d: %d\n",
 				ec_dev->irq, err);
 			return err;
 		}
@@ -267,7 +267,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 	 */
 	err = cros_ec_sleep_event(ec_dev, 0);
 	if (err < 0)
-		dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
+		dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec\n",
 			err);
 
 	if (ec_dev->mkbp_event_supported) {
@@ -338,7 +338,7 @@ int cros_ec_suspend(struct cros_ec_device *ec_dev)
 
 	ret = cros_ec_sleep_event(ec_dev, sleep_event);
 	if (ret < 0)
-		dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec",
+		dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec\n",
 			ret);
 
 	if (device_may_wakeup(dev))
@@ -381,7 +381,7 @@ int cros_ec_resume(struct cros_ec_device *ec_dev)
 
 	ret = cros_ec_sleep_event(ec_dev, sleep_event);
 	if (ret < 0)
-		dev_dbg(ec_dev->dev, "Error %d sending resume event to ec",
+		dev_dbg(ec_dev->dev, "Error %d sending resume event to ec\n",
 			ret);
 
 	if (ec_dev->wake_enabled)
-- 
2.35.1.265.g69c8d7142f-goog

Re: [PATCH v4 1/5] platform/chrome: cros_ec: fix error handling in cros_ec_register()

[Prashant Malani]

On Tue, Feb 15, 2022 at 8:36 PM Tzung-Bi Shih <tzungbi@google.com> wrote:
>
> Fix cros_ec_register() to unregister platform devices if
> blocking_notifier_chain_register() fails.
>
> Also use the single exit path to handle the platform device
> unregistration.
>
> Fixes: 42cd0ab476e2 ("platform/chrome: cros_ec: Query EC protocol version if EC transitions between RO/RW")
> Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Reviewed-by: Prashant Malani <pmalani@chromium.org>

> ---
> Changes from v3:
> (https://patchwork.kernel.org/project/chrome-platform/patch/20220209095703.517608-2-tzungbi@google.com/)
> - Simplify by initializing the variables at the beginning.
>
> Changes from v2:
> (https://patchwork.kernel.org/project/chrome-platform/patch/20220209045035.380615-2-tzungbi@google.com/)
> - Fix grammar error in commit message.
> - Change the code that don't rely on zeroed memory.
> - Remove unnecessary `if` checks before calling platform_device_unregister().
>
> Changes from v1:
> (https://lore.kernel.org/lkml/20220125101527.1812887-1-tzungbi@google.com/T/#u)
> - Use imperative mood in commit message.
> - Use IS_ERR_OR_NULL() in 1st patch.
>
>  drivers/platform/chrome/cros_ec.c | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
> index fc5aa1525d13..ff2a24b0c611 100644
> --- a/drivers/platform/chrome/cros_ec.c
> +++ b/drivers/platform/chrome/cros_ec.c
> @@ -189,6 +189,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>         ec_dev->max_request = sizeof(struct ec_params_hello);
>         ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
>         ec_dev->max_passthru = 0;
> +       ec_dev->ec = NULL;
> +       ec_dev->pd = NULL;
>
>         ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
>         if (!ec_dev->din)
> @@ -245,18 +247,16 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>                 if (IS_ERR(ec_dev->pd)) {
>                         dev_err(ec_dev->dev,
>                                 "Failed to create CrOS PD platform device\n");
> -                       platform_device_unregister(ec_dev->ec);
> -                       return PTR_ERR(ec_dev->pd);
> +                       err = PTR_ERR(ec_dev->pd);
> +                       goto exit;
>                 }
>         }
>
>         if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
>                 err = devm_of_platform_populate(dev);
>                 if (err) {
> -                       platform_device_unregister(ec_dev->pd);
> -                       platform_device_unregister(ec_dev->ec);
>                         dev_err(dev, "Failed to register sub-devices\n");
> -                       return err;
> +                       goto exit;
>                 }
>         }
>
> @@ -278,7 +278,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>                 err = blocking_notifier_chain_register(&ec_dev->event_notifier,
>                                                       &ec_dev->notifier_ready);
>                 if (err)
> -                       return err;
> +                       goto exit;
>         }
>
>         dev_info(dev, "Chrome EC device registered\n");
> @@ -291,6 +291,10 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>                 cros_ec_irq_thread(0, ec_dev);
>
>         return 0;
> +exit:
> +       platform_device_unregister(ec_dev->ec);
> +       platform_device_unregister(ec_dev->pd);
> +       return err;
>  }
>  EXPORT_SYMBOL(cros_ec_register);
>
> --
> 2.35.1.265.g69c8d7142f-goog
>

Re: [PATCH v4 3/5] platform/chrome: cros_ec: initialize `wake_enabled` in cros_ec_register()

[Prashant Malani]

On Tue, Feb 15, 2022 at 8:37 PM Tzung-Bi Shih <tzungbi@google.com> wrote:
>
> `wake_enabled` indicates cros_ec_resume() needs to call
> disable_irq_wake() to undo enable_irq_wake() in cros_ec_suspend().
>
> Initialize `wake_enabled` in cros_ec_register() and determine the flag
> in cros_ec_suspend() instead of reset-after-used in cros_ec_resume().
>
> Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>

One minor thing to consider, but regardless:

Reviewed-by: Prashant Malani <pmalani@chromium.org>

> ---
> Changes from v3:
> (https://patchwork.kernel.org/project/chrome-platform/patch/20220209095703.517608-4-tzungbi@google.com/)
> - Change the patch title.
> - Simplify by initializing wake_enabled in cros_ec_register().
>
> No changes from v2.
>
> Changes from v1:
> (https://lore.kernel.org/lkml/20220125101527.1812887-1-tzungbi@google.com/T/#u)
> - Use imperative mood in commit message.
>
>  drivers/platform/chrome/cros_ec.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
> index 25cd8df6e7b0..b6604a9ab315 100644
> --- a/drivers/platform/chrome/cros_ec.c
> +++ b/drivers/platform/chrome/cros_ec.c
> @@ -191,6 +191,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>         ec_dev->max_passthru = 0;
>         ec_dev->ec = NULL;
>         ec_dev->pd = NULL;
> +       ec_dev->wake_enabled = false;
>
>         ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
>         if (!ec_dev->din)
> @@ -383,10 +384,9 @@ int cros_ec_resume(struct cros_ec_device *ec_dev)
>                 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec",
>                         ret);
>
> -       if (ec_dev->wake_enabled) {
> +       if (ec_dev->wake_enabled)
>                 disable_irq_wake(ec_dev->irq);
> -               ec_dev->wake_enabled = 0;
> -       }
> +

Better to leave it as is, and ensure "wake_enabled" is cleared after resume?
Will result in a smaller diff.

I'll leave it up to you.

-Prashant

Re: [PATCH v4 3/5] platform/chrome: cros_ec: initialize `wake_enabled` in cros_ec_register()

[Tzung-Bi Shih]

On Tue, Feb 15, 2022 at 09:47:09PM -0800, Prashant Malani wrote:
> On Tue, Feb 15, 2022 at 8:37 PM Tzung-Bi Shih <tzungbi@google.com> wrote:
> >
> > `wake_enabled` indicates cros_ec_resume() needs to call
> > disable_irq_wake() to undo enable_irq_wake() in cros_ec_suspend().
> >
> > Initialize `wake_enabled` in cros_ec_register() and determine the flag
> > in cros_ec_suspend() instead of reset-after-used in cros_ec_resume().

After reconsidering the 2 options in [1], I feel the flag needs to be set in
cros_ec_suspend() just in case if someone changes the wakeup capability per
[2].

[1]: https://patchwork.kernel.org/project/chrome-platform/patch/20220209045035.380615-4-tzungbi@google.com/#24739778
[2]: https://patchwork.kernel.org/project/chrome-platform/patch/20220209045035.380615-4-tzungbi@google.com/#24740205

Will change it back in the next version, pardon me.

> > @@ -383,10 +384,9 @@ int cros_ec_resume(struct cros_ec_device *ec_dev)
> >                 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec",
> >                         ret);
> >
> > -       if (ec_dev->wake_enabled) {
> > +       if (ec_dev->wake_enabled)
> >                 disable_irq_wake(ec_dev->irq);
> > -               ec_dev->wake_enabled = 0;
> > -       }
> > +
> 
> Better to leave it as is, and ensure "wake_enabled" is cleared after resume?
> Will result in a smaller diff.

No, cros_ec_suspend() uses the flag to tell cros_ec_resume(): don't forget to
call disable_irq_wake().  It shouldn't be reset after used by
cros_ec_resume().