diff mbox series

[v3,16/23] platform/chrome: cros_ec_proto: return 0 on getting cmd mask success

Message ID 20220608110734.2928245-17-tzungbi@kernel.org (mailing list archive)
State Superseded
Headers show
Series platform/chrome: Kunit tests and refactor for cros_ec_query_all() | expand

Commit Message

Tzung-Bi Shih June 8, 2022, 11:07 a.m. UTC 
cros_ec_get_host_command_version_mask() used to return value from
send_command() which is number of available bytes for input payload on
success (i.e. sizeof(struct ec_response_get_cmd_versions)).

However, the callers don't need to know how many bytes are available.

Don't return number of available bytes.  Instead, return 0 on success;
otherwise, negative integers on error.

Also remove the unneeded `ver_mask` initialization as the callers should
take it only if cros_ec_get_host_command_version_mask() returns 0.

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
Changes from v2:
- Separate Kunit test to another patch.
- Rephrase the commit message.

Changes from v1:
- Return 0 on success; otherwise, negative intergers.

 drivers/platform/chrome/cros_ec_proto.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

Comments

Guenter Roeck June 8, 2022, 4:20 p.m. UTC | #1 
On Wed, Jun 8, 2022 at 4:08 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
>
> cros_ec_get_host_command_version_mask() used to return value from
> send_command() which is number of available bytes for input payload on
> success (i.e. sizeof(struct ec_response_get_cmd_versions)).
>
> However, the callers don't need to know how many bytes are available.
>
> Don't return number of available bytes.  Instead, return 0 on success;
> otherwise, negative integers on error.
>
> Also remove the unneeded `ver_mask` initialization as the callers should
> take it only if cros_ec_get_host_command_version_mask() returns 0.

Make sure this compiles with W=1. Compilers may think that ver_mask
may be uninitialized when used.

>
> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

Otherwise

Reviewed-by: Guenter Roeck <groeck@chromium.org>

> ---
> Changes from v2:
> - Separate Kunit test to another patch.
> - Rephrase the commit message.
>
> Changes from v1:
> - Return 0 on success; otherwise, negative intergers.
>
>  drivers/platform/chrome/cros_ec_proto.c | 13 +++++--------
>  1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index efbabdcb31ae..06bc7db1213e 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -453,6 +453,7 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
>         if (ret > 0) {
>                 rver = (struct ec_response_get_cmd_versions *)msg->data;
>                 *mask = rver->version_mask;
> +               ret = 0;
>         }
>
>         kfree(msg);
> @@ -469,7 +470,7 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
>   */
>  int cros_ec_query_all(struct cros_ec_device *ec_dev)
>  {
> -       u32 ver_mask = 0;
> +       u32 ver_mask;
>         int ret;
>
>         /* First try sending with proto v3. */
> @@ -505,9 +506,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
>                 return -ENOMEM;
>
>         /* Probe if MKBP event is supported */
> -       ret = cros_ec_get_host_command_version_mask(ec_dev,
> -                                                   EC_CMD_GET_NEXT_EVENT,
> -                                                   &ver_mask);
> +       ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_GET_NEXT_EVENT, &ver_mask);
>         if (ret < 0 || ver_mask == 0) {
>                 ec_dev->mkbp_event_supported = 0;
>         } else {
> @@ -517,10 +516,8 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
>         }
>
>         /* Probe if host sleep v1 is supported for S0ix failure detection. */
> -       ret = cros_ec_get_host_command_version_mask(ec_dev,
> -                                                   EC_CMD_HOST_SLEEP_EVENT,
> -                                                   &ver_mask);
> -       ec_dev->host_sleep_v1 = (ret >= 0 && (ver_mask & EC_VER_MASK(1)));
> +       ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_HOST_SLEEP_EVENT, &ver_mask);
> +       ec_dev->host_sleep_v1 = (ret == 0 && (ver_mask & EC_VER_MASK(1)));
>
>         /* Get host event wake mask. */
>         ret = cros_ec_get_host_event_wake_mask(ec_dev, &ec_dev->host_event_wake_mask);
> --
> 2.36.1.255.ge46751e96f-goog
>
Tzung-Bi Shih June 9, 2022, 8:44 a.m. UTC | #2 
On Wed, Jun 08, 2022 at 09:20:29AM -0700, Guenter Roeck wrote:
> On Wed, Jun 8, 2022 at 4:08 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
> >
> > cros_ec_get_host_command_version_mask() used to return value from
> > send_command() which is number of available bytes for input payload on
> > success (i.e. sizeof(struct ec_response_get_cmd_versions)).
> >
> > However, the callers don't need to know how many bytes are available.
> >
> > Don't return number of available bytes.  Instead, return 0 on success;
> > otherwise, negative integers on error.
> >
> > Also remove the unneeded `ver_mask` initialization as the callers should
> > take it only if cros_ec_get_host_command_version_mask() returns 0.
> 
> Make sure this compiles with W=1. Compilers may think that ver_mask
> may be uninitialized when used.

If I tested it correctly, it compiles.

$ make mrproper
$ make allmodconfig
$ make W=1 drivers/platform/chrome/
...
  CC      drivers/platform/chrome/cros_ec_proto.o
  CC      drivers/platform/chrome/cros_ec_trace.o
  AR      drivers/platform/chrome/built-in.a
  CC [M]  drivers/platform/chrome/chromeos_acpi.o
  CC [M]  drivers/platform/chrome/chromeos_laptop.o
  CC [M]  drivers/platform/chrome/chromeos_privacy_screen.o
  CC [M]  drivers/platform/chrome/chromeos_pstore.o
  CC [M]  drivers/platform/chrome/chromeos_tbmc.o
  CC [M]  drivers/platform/chrome/cros_ec.o
...
diff mbox series

Patch

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index efbabdcb31ae..06bc7db1213e 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -453,6 +453,7 @@  static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
 	if (ret > 0) {
 		rver = (struct ec_response_get_cmd_versions *)msg->data;
 		*mask = rver->version_mask;
+		ret = 0;
 	}
 
 	kfree(msg);
@@ -469,7 +470,7 @@  static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
  */
 int cros_ec_query_all(struct cros_ec_device *ec_dev)
 {
-	u32 ver_mask = 0;
+	u32 ver_mask;
 	int ret;
 
 	/* First try sending with proto v3. */
@@ -505,9 +506,7 @@  int cros_ec_query_all(struct cros_ec_device *ec_dev)
 		return -ENOMEM;
 
 	/* Probe if MKBP event is supported */
-	ret = cros_ec_get_host_command_version_mask(ec_dev,
-						    EC_CMD_GET_NEXT_EVENT,
-						    &ver_mask);
+	ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_GET_NEXT_EVENT, &ver_mask);
 	if (ret < 0 || ver_mask == 0) {
 		ec_dev->mkbp_event_supported = 0;
 	} else {
@@ -517,10 +516,8 @@  int cros_ec_query_all(struct cros_ec_device *ec_dev)
 	}
 
 	/* Probe if host sleep v1 is supported for S0ix failure detection. */
-	ret = cros_ec_get_host_command_version_mask(ec_dev,
-						    EC_CMD_HOST_SLEEP_EVENT,
-						    &ver_mask);
-	ec_dev->host_sleep_v1 = (ret >= 0 && (ver_mask & EC_VER_MASK(1)));
+	ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_HOST_SLEEP_EVENT, &ver_mask);
+	ec_dev->host_sleep_v1 = (ret == 0 && (ver_mask & EC_VER_MASK(1)));
 
 	/* Get host event wake mask. */
 	ret = cros_ec_get_host_event_wake_mask(ec_dev, &ec_dev->host_event_wake_mask);