Re: [PATCH 2/2] drm/amd/pm: Add helper for parameter parsing

[Tvrtko Ursulin]

On 29/05/2026 10:38, Lijo Lazar wrote:

Add a helper function to extract long values passed in a string. The
string may have values of multiple parameters separated by space char.

Hah! :) Long time ago, in a galaxy not so far away:

https://patchwork.freedesktop.org/series/154657/

Regards,

Tvrtko

Signed-off-by: Lijo Lazar <lijo.la...@amd.com>
---
  drivers/gpu/drm/amd/pm/amdgpu_pm.c | 116 ++++++++++++-----------------
  1 file changed, 48 insertions(+), 68 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/amdgpu_pm.c 
b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
index ebe0b320ca4f..040839dc6368 100644
--- a/drivers/gpu/drm/amd/pm/amdgpu_pm.c
+++ b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
@@ -98,6 +98,37 @@ const char * const amdgpu_pp_profile_name[] = {
        "UNCAPPED",
  };

+static int amdgpu_pm_parse_long_params(char *str, long *params,

+                                      uint32_t max_params,
+                                      uint32_t *num_params)
+{
+       const char delimiter[] = { ' ', '\n', '\0' };
+       uint32_t count = 0;
+       char *sub_str;
+       int ret;
+
+       if (!params || !num_params)
+               return -EINVAL;
+
+       while ((sub_str = strsep(&str, delimiter)) != NULL) {
+               if (strlen(sub_str) == 0)
+                       continue;
+               if (count >= max_params)
+                       return -EINVAL;
+               ret = kstrtol(sub_str, 0, &params[count]);
+               if (ret)
+                       return -EINVAL;
+               count++;
+               if (!str)
+                       break;
+               while (isspace(*str))
+                       str++;
+       }
+       *num_params = count;
+
+       return 0;
+}
+
  /**
   * amdgpu_pm_dev_state_check - Check if device can be accessed.
   * @adev: Target device.
@@ -759,8 +790,6 @@ static ssize_t amdgpu_set_pp_od_clk_voltage(struct device 
*dev,
        long parameter[64];
        char buf_cpy[128];
        char *tmp_str;
-       char *sub_str;
-       const char delimiter[3] = {' ', '\n', '\0'};
        uint32_t type;

if (count > 127 || count == 0)

@@ -795,22 +824,10 @@ static ssize_t amdgpu_set_pp_od_clk_voltage(struct device 
*dev,
                tmp_str++;
        while (isspace(*++tmp_str));

- while ((sub_str = strsep(&tmp_str, delimiter)) != NULL) {

-               if (strlen(sub_str) == 0)
-                       continue;
-               if (parameter_size >= ARRAY_SIZE(parameter))
-                       return -EINVAL;
-               ret = kstrtol(sub_str, 0, &parameter[parameter_size]);
-               if (ret)
-                       return -EINVAL;
-               parameter_size++;
-
-               if (!tmp_str)
-                       break;
-
-               while (isspace(*tmp_str))
-                       tmp_str++;
-       }
+       ret = amdgpu_pm_parse_long_params(
+               tmp_str, parameter, ARRAY_SIZE(parameter), &parameter_size);
+       if (ret)
+               return ret;

ret = amdgpu_pm_get_access(adev);

        if (ret < 0)
@@ -1373,11 +1390,9 @@ static ssize_t amdgpu_set_pp_power_profile_mode(struct 
device *dev,
        struct amdgpu_device *adev = drm_to_adev(ddev);
        uint32_t parameter_size = 0;
        long parameter[64];
-       char *sub_str, buf_cpy[128];
-       char *tmp_str;
+       char buf_cpy[128];
        char tmp[2];
        long int profile_mode = 0;
-       const char delimiter[3] = {' ', '\n', '\0'};

tmp[0] = *(buf++);

        tmp[1] = '\0';
@@ -1391,19 +1406,11 @@ static ssize_t amdgpu_set_pp_power_profile_mode(struct 
device *dev,
                while (isspace(*buf))
                        buf++;
                strscpy(buf_cpy, buf, sizeof(buf_cpy));
-               tmp_str = buf_cpy;
-               while ((sub_str = strsep(&tmp_str, delimiter)) != NULL) {
-                       if (strlen(sub_str) == 0)
-                               continue;
-                       ret = kstrtol(sub_str, 0, &parameter[parameter_size]);
-                       if (ret)
-                               return -EINVAL;
-                       parameter_size++;
-                       if (!tmp_str)
-                               break;
-                       while (isspace(*tmp_str))
-                               tmp_str++;
-               }
+               ret = amdgpu_pm_parse_long_params(buf_cpy, parameter,
+                                                 ARRAY_SIZE(parameter) - 1,
+                                                 &parameter_size);
+               if (ret)
+                       return ret;
        }
        parameter[parameter_size] = profile_mode;

@@ -3928,18 +3935,14 @@ static int amdgpu_retrieve_od_settings(struct amdgpu_device *adev,

        return size;
  }

-static int parse_input_od_command_lines(const char *buf,

-                                       size_t count,
-                                       u32 *type,
-                                       long *params,
-                                       size_t params_max,
+static int parse_input_od_command_lines(const char *buf, size_t count,
+                                       u32 *type, long *params,
+                                       uint32_t max_params,
                                        uint32_t *num_of_params)
  {
-       const char delimiter[3] = {' ', '\n', '\0'};
        uint32_t parameter_size = 0;
        char buf_cpy[128] = {0};
-       char *tmp_str, *sub_str;
-       int ret;
+       char *tmp_str;

if (count > sizeof(buf_cpy) - 1)

                return -EINVAL;
@@ -3964,28 +3967,8 @@ static int parse_input_od_command_lines(const char *buf,
                break;
        }

- while ((sub_str = strsep(&tmp_str, delimiter)) != NULL) {

-               if (strlen(sub_str) == 0)
-                       continue;
-
-               if (parameter_size >= params_max)
-                       return -EINVAL;
-
-               ret = kstrtol(sub_str, 0, &params[parameter_size]);
-               if (ret)
-                       return -EINVAL;
-               parameter_size++;
-
-               if (!tmp_str)
-                       break;
-
-               while (isspace(*tmp_str))
-                       tmp_str++;
-       }
-
-       *num_of_params = parameter_size;
-
-       return 0;
+       return amdgpu_pm_parse_long_params(tmp_str, params, max_params,
+                                          num_of_params);
  }

static int

@@ -3998,10 +3981,7 @@ amdgpu_distribute_custom_od_settings(struct 
amdgpu_device *adev,
        long parameter[64];
        int ret;

- ret = parse_input_od_command_lines(in_buf,

-                                          count,
-                                          &cmd_type,
-                                          parameter,
+       ret = parse_input_od_command_lines(in_buf, count, &cmd_type, parameter,
                                           ARRAY_SIZE(parameter),
                                           &parameter_size);
        if (ret)