diff mbox series

[v2,02/19] ACPI: LPIT: move to use bus_get_dev_root()

Message ID 20230322083646.2937580-1-gregkh@linuxfoundation.org
State New
Headers
Series None |

Commit Message

Greg KH March 22, 2023, 8:36 a.m. UTC 
  Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
v2: - change logic to test for dev_root at the beginning of the function
      and error out then based on review comments from Rafael.
    - fix error handling for ioremap() call to properly drop the
      reference on dev_root if it failed.

 drivers/acpi/acpi_lpit.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

Comments

Rafael J. Wysocki March 22, 2023, 2:15 p.m. UTC | #1 
On Wed, Mar 22, 2023 at 9:36 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> Direct access to the struct bus_type dev_root pointer is going away soon
> so replace that with a call to bus_get_dev_root() instead, which is what
> it is there for.
>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Len Brown <lenb@kernel.org>
> Cc: linux-acpi@vger.kernel.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> ---
> v2: - change logic to test for dev_root at the beginning of the function
>       and error out then based on review comments from Rafael.
>     - fix error handling for ioremap() call to properly drop the
>       reference on dev_root if it failed.
>
>  drivers/acpi/acpi_lpit.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/acpi/acpi_lpit.c b/drivers/acpi/acpi_lpit.c
> index 3843d2576d3f..c5598b6d5db8 100644
> --- a/drivers/acpi/acpi_lpit.c
> +++ b/drivers/acpi/acpi_lpit.c
> @@ -98,6 +98,12 @@ EXPORT_SYMBOL_GPL(lpit_read_residency_count_address);
>  static void lpit_update_residency(struct lpit_residency_info *info,
>                                  struct acpi_lpit_native *lpit_native)
>  {
> +       struct device *dev_root = bus_get_dev_root(&cpu_subsys);
> +
> +       /* Silently fail, if cpuidle attribute group is not present */
> +       if (!dev_root)
> +               return;
> +
>         info->frequency = lpit_native->counter_frequency ?
>                                 lpit_native->counter_frequency : tsc_khz * 1000;
>         if (!info->frequency)
> @@ -108,18 +114,18 @@ static void lpit_update_residency(struct lpit_residency_info *info,
>                 info->iomem_addr = ioremap(info->gaddr.address,
>                                                    info->gaddr.bit_width / 8);
>                 if (!info->iomem_addr)
> -                       return;
> +                       goto exit;
>
> -               /* Silently fail, if cpuidle attribute group is not present */
> -               sysfs_add_file_to_group(&cpu_subsys.dev_root->kobj,
> +               sysfs_add_file_to_group(&dev_root->kobj,
>                                         &dev_attr_low_power_idle_system_residency_us.attr,
>                                         "cpuidle");
>         } else if (info->gaddr.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
> -               /* Silently fail, if cpuidle attribute group is not present */
> -               sysfs_add_file_to_group(&cpu_subsys.dev_root->kobj,
> +               sysfs_add_file_to_group(&dev_root->kobj,
>                                         &dev_attr_low_power_idle_cpu_residency_us.attr,
>                                         "cpuidle");
>         }
> +exit:
> +       put_device(dev_root);
>  }
>
>  static void lpit_process(u64 begin, u64 end)
> --
> 2.40.0
>
diff mbox series

Patch

diff --git a/drivers/acpi/acpi_lpit.c b/drivers/acpi/acpi_lpit.c
index 3843d2576d3f..c5598b6d5db8 100644
--- a/drivers/acpi/acpi_lpit.c
+++ b/drivers/acpi/acpi_lpit.c
@@ -98,6 +98,12 @@  EXPORT_SYMBOL_GPL(lpit_read_residency_count_address);
 static void lpit_update_residency(struct lpit_residency_info *info,
 				 struct acpi_lpit_native *lpit_native)
 {
+	struct device *dev_root = bus_get_dev_root(&cpu_subsys);
+
+	/* Silently fail, if cpuidle attribute group is not present */
+	if (!dev_root)
+		return;
+
 	info->frequency = lpit_native->counter_frequency ?
 				lpit_native->counter_frequency : tsc_khz * 1000;
 	if (!info->frequency)
@@ -108,18 +114,18 @@  static void lpit_update_residency(struct lpit_residency_info *info,
 		info->iomem_addr = ioremap(info->gaddr.address,
 						   info->gaddr.bit_width / 8);
 		if (!info->iomem_addr)
-			return;
+			goto exit;
 
-		/* Silently fail, if cpuidle attribute group is not present */
-		sysfs_add_file_to_group(&cpu_subsys.dev_root->kobj,
+		sysfs_add_file_to_group(&dev_root->kobj,
 					&dev_attr_low_power_idle_system_residency_us.attr,
 					"cpuidle");
 	} else if (info->gaddr.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
-		/* Silently fail, if cpuidle attribute group is not present */
-		sysfs_add_file_to_group(&cpu_subsys.dev_root->kobj,
+		sysfs_add_file_to_group(&dev_root->kobj,
 					&dev_attr_low_power_idle_cpu_residency_us.attr,
 					"cpuidle");
 	}
+exit:
+	put_device(dev_root);
 }
 
 static void lpit_process(u64 begin, u64 end)