On Wed, 31 Jul 2024, Srinivas Pandruvada wrote:
> After commit '1630dc626c87 ("platform/x86: ISST: Add model specific
> loading for common module")' isst_misc_reg() and isst_misc_unreg() can be
> simplified. Since these functions are only called during module_init()
> and module_exit() respectively, there is no contention while calling
> misc_register()/misc_deregister or isst_if_cpu_info_init()/
> isst_if_cpu_info_exit().
>
> Hence remove mutex and reference counting.
>
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
> ---
> .../intel/speed_select_if/isst_if_common.c | 42 +++++--------------
> 1 file changed, 11 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/platform/x86/intel/speed_select_if/isst_if_common.c b/drivers/platform/x86/intel/speed_select_if/isst_if_common.c
> index 3065f149e721..febfd5eeceb4 100644
> --- a/drivers/platform/x86/intel/speed_select_if/isst_if_common.c
> +++ b/drivers/platform/x86/intel/speed_select_if/isst_if_common.c
> @@ -651,10 +651,6 @@ static long isst_if_def_ioctl(struct file *file, unsigned int cmd,
>
> /* Lock to prevent module registration when already opened by user space */
> static DEFINE_MUTEX(punit_misc_dev_open_lock);
> -/* Lock to allow one shared misc device for all ISST interfaces */
> -static DEFINE_MUTEX(punit_misc_dev_reg_lock);
> -static int misc_usage_count;
> -static int misc_device_ret;
> static int misc_device_open;
>
> static int isst_if_open(struct inode *inode, struct file *file)
> @@ -720,39 +716,23 @@ static struct miscdevice isst_if_char_driver = {
>
> static int isst_misc_reg(void)
> {
> - mutex_lock(&punit_misc_dev_reg_lock);
> - if (misc_device_ret)
> - goto unlock_exit;
> -
> - if (!misc_usage_count) {
> - misc_device_ret = isst_if_cpu_info_init();
> - if (misc_device_ret)
> - goto unlock_exit;
> -
> - misc_device_ret = misc_register(&isst_if_char_driver);
> - if (misc_device_ret) {
> - isst_if_cpu_info_exit();
> - goto unlock_exit;
> - }
> - }
> - misc_usage_count++;
> + int ret;
>
> -unlock_exit:
> - mutex_unlock(&punit_misc_dev_reg_lock);
> + ret = isst_if_cpu_info_init();
> + if (ret)
> + return ret;
>
> - return misc_device_ret;
> + ret = misc_register(&isst_if_char_driver);
> + if (ret)
> + isst_if_cpu_info_exit();
> +
> + return ret;
> }
>
> static void isst_misc_unreg(void)
> {
> - mutex_lock(&punit_misc_dev_reg_lock);
> - if (misc_usage_count)
> - misc_usage_count--;
> - if (!misc_usage_count && !misc_device_ret) {
> - misc_deregister(&isst_if_char_driver);
> - isst_if_cpu_info_exit();
> - }
> - mutex_unlock(&punit_misc_dev_reg_lock);
> + misc_deregister(&isst_if_char_driver);
> + isst_if_cpu_info_exit();
> }
>
> /**
>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
--
i.
