AMD General

> -----Original Message-----
> From: Alex Deucher <[email protected]>
> Sent: Monday, June 15, 2026 11:26 PM
> To: Lazar, Lijo <[email protected]>
> Cc: Wang, Yang(Kevin) <[email protected]>; amd-
> [email protected]; Deucher, Alexander
> <[email protected]>; Zhang, Hawking
> <[email protected]>; Feng, Kenneth <[email protected]>;
> Liu, Shuzhou (Bill) <[email protected]>; Arif, Maisam
> <[email protected]>
> Subject: Re: [PATCH] drm/amd/pm: refactor DPM clock level reporting
>
> On Tue, Jun 9, 2026 at 8:20 AM Lazar, Lijo <[email protected]> wrote:
> >
> >
> >
> > On 09-Jun-26 5:35 PM, Wang, Yang(Kevin) wrote:
> > > AMD General
> > >
> > >> -----Original Message-----
> > >> From: Lazar, Lijo <[email protected]>
> > >> Sent: Tuesday, June 9, 2026 7:12 PM
> > >> To: Wang, Yang(Kevin) <[email protected]>; amd-
> > >> [email protected]
> > >> Cc: Deucher, Alexander <[email protected]>; Zhang,
> Hawking
> > >> <[email protected]>; Feng, Kenneth
> <[email protected]>; Liu,
> > >> Shuzhou (Bill) <[email protected]>; Arif, Maisam
> > >> <[email protected]>
> > >> Subject: Re: [PATCH] drm/amd/pm: refactor DPM clock level reporting
> > >>
> > >>
> > >>
> > >> On 09-Jun-26 3:49 PM, Wang, Yang(Kevin) wrote:
> > >>> AMD General
> > >>>
> > >>>> -----Original Message-----
> > >>>> From: Lazar, Lijo <[email protected]>
> > >>>> Sent: Tuesday, June 9, 2026 4:11 PM
> > >>>> To: Wang, Yang(Kevin) <[email protected]>; amd-
> > >>>> [email protected]
> > >>>> Cc: Deucher, Alexander <[email protected]>; Zhang,
> > >>>> Hawking <[email protected]>; Feng, Kenneth
> > >>>> <[email protected]>
> > >>>> Subject: Re: [PATCH] drm/amd/pm: refactor DPM clock level
> > >>>> reporting
> > >>>>
> > >>>>
> > >>>>
> > >>>> On 09-Jun-26 12:21 PM, Yang Wang wrote:
> > >>>>> Refactor smu_cmn_print_dpm_clk_levels() to build clock entries
> > >>>>> before emitting sysfs output.
> > >>>>>
> > >>>>> For discrete DPM tables, mark the level closest to the reported
> > >>>>> current clock. This avoids losing the active '*' marker when the
> > >>>>> SMU-reported clock does not fall within the previous fixed tolerance.
> > >>>>>
> > >>>>> Keep fine-grained output explicit by reporting the current clock
> > >>>>> on an 'F' line, and keep deep sleep represented by the 'S' line
> > >>>>> without marking a discrete level.
> > >>>>>
> > >>>>> Active marker placement:
> > >>>>>
> > >>>>> | Mode         | '*' marker location       | Reason                   
> > >>>>>  |
> > >>>>> | ------------ | ------------------------- | 
> > >>>>> ------------------------- |
> > >>>>> | discrete     | closest/current DPM level | entries are real levels  
> > >>>>>  |
> > >>>>> | fine-grained | 'F:' current clock line   | min/max are range bounds 
> > >>>>>  |
> > >>>>> | deep sleep   | 'S:' line                 | outside normal DPM range 
> > >>>>>  |
> > >>>>>
> > >>>>> Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5295
> > >>>>> Signed-off-by: Yang Wang <[email protected]>
> > >>>>> ---
> > >>>>>     drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 148
> > >> +++++++++++++++++--
> > >>>> ------
> > >>>>>     1 file changed, 101 insertions(+), 47 deletions(-)
> > >>>>>
> > >>>>> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> > >>>>> b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> > >>>>> index d365f06ac1ac..872c0328f290 100644
> > >>>>> --- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> > >>>>> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> > >>>>> @@ -1376,77 +1376,131 @@ void
> smu_cmn_reset_custom_level(struct
> > >>>> smu_context *smu)
> > >>>>>       pstate_table->uclk_pstate.custom.max = 0;
> > >>>>>     }
> > >>>>>
> > >>>>> -static inline bool smu_cmn_freqs_match(uint32_t freq1, uint32_t
> > >>>>> freq2)
> > >>>>> +struct smu_clk_print_entry {
> > >>>>> +   uint32_t freq;
> > >>>>> +   bool selected;
> > >>>>> +};
> > >>>>> +
> > >>>>> +static inline uint32_t smu_cmn_freq_distance(uint32_t freq1,
> > >>>>> +uint32_t
> > >>>>> +freq2) {
> > >>>>> +   return freq1 > freq2 ? freq1 - freq2 : freq2 - freq1; }
> > >>>>> +
> > >>>>> +static inline uint32_t smu_cmn_get_dpm_level_count(struct
> > >>>>> +smu_dpm_table *dpm_table) {
> > >>>>> +   return min_t(uint32_t, dpm_table->count,
> > >>>> SMU_MAX_DPM_LEVELS); }
> > >>>>> +
> > >>>>> +static uint32_t smu_cmn_get_closest_clk_level(struct
> > >>>>> +smu_dpm_table *dpm_table, uint32_t cur_clk) {
> > >>>>> +   uint32_t min_distance, distance;
> > >>>>> +   uint32_t closest_level = 0;
> > >>>>> +   uint32_t count;
> > >>>>> +   uint32_t i;
> > >>>>> +
> > >>>>> +   count = smu_cmn_get_dpm_level_count(dpm_table);
> > >>>>> +   if (!count)
> > >>>>> +           return SMU_MAX_DPM_LEVELS;
> > >>>>> +
> > >>>>> +   min_distance = smu_cmn_freq_distance(cur_clk, dpm_table-
> > >>>>> dpm_levels[0].value);
> > >>>>> +   for (i = 1; i < count; i++) {
> > >>>>> +           distance = smu_cmn_freq_distance(cur_clk, dpm_table-
> > >>>>> dpm_levels[i].value);
> > >>>>> +           if (distance < min_distance) {
> > >>>>> +                   min_distance = distance;
> > >>>>> +                   closest_level = i;
> > >>>>> +           }
> > >>>>> +   }
> > >>>>> +
> > >>>>> +   return closest_level;
> > >>>>> +}
> > >>>>> +
> > >>>>> +static inline int smu_cmn_emit_clk_line(char *buf, int size,
> > >>>>> +                                   int level_index, uint32_t
> > >>>>> +freq, bool
> > >>>> selected) {
> > >>>>> +   return sysfs_emit_at(buf, size, "%d: %uMhz %s\n",
> > >>>>> +                        level_index, freq, selected ? "*" :
> > >>>>> + ""); }
> > >>>>> +
> > >>>>> +static void smu_cmn_build_fine_grained_levels(uint32_t min_clk,
> > >>>>> +uint32_t
> > >>>> max_clk,
> > >>>>> +                                         struct
> > >>>>> + smu_clk_print_entry
> > >>>> *entries,
> > >>>>> +                                         uint32_t *entry_count) {
> > >>>>> +   *entry_count = 2;
> > >>>>> +   entries[0].freq = min_clk;
> > >>>>> +   entries[0].selected = false;
> > >>>>> +   entries[1].freq = max_clk;
> > >>>>> +   entries[1].selected = false; }
> > >>>>> +
> > >>>>> +static void smu_cmn_build_discrete_levels(struct smu_dpm_table
> > >>>> *dpm_table,
> > >>>>> +                                     uint32_t selected_level,
> > >>>>> +                                     struct smu_clk_print_entry 
> > >>>>> *entries,
> > >>>>> +                                     uint32_t *entry_count) {
> > >>>>> +   uint32_t i;
> > >>>>> +
> > >>>>> +   *entry_count = smu_cmn_get_dpm_level_count(dpm_table);
> > >>>>> +
> > >>>>> +   for (i = 0; i < *entry_count; i++) {
> > >>>>> +           entries[i].freq = dpm_table->dpm_levels[i].value;
> > >>>>> +           entries[i].selected = (i == selected_level);
> > >>>>> +   }
> > >>>>> +}
> > >>>>> +
> > >>>>> +static int smu_cmn_emit_clk_prefix(char *buf, int size,
> > >>>>> +                              bool is_fine_grained, bool 
> > >>>>> is_deep_sleep,
> > >>>>> +                              uint32_t cur_clk)
> > >>>>>     {
> > >>>>> -   /* Frequencies within 25 MHz are considered equal */
> > >>>>> -   return (abs((int)freq1 - (int)freq2) <= 25);
> > >>>>> +   if (is_deep_sleep)
> > >>>>> +           size += sysfs_emit_at(buf, size, "S: %uMhz *\n", cur_clk);
> > >>>>> +   else if (is_fine_grained)
> > >>>>> +           size += sysfs_emit_at(buf, size, "F: %uMhz *\n",
> > >>>>> + cur_clk);
> > >>>>
> > >>>> What about keeping the else part as C: <cur_clk> in all cases -
> > >>>> instead of just fine grained? * indicates the closest level
> > >>>> matched and cur_clk will give the exact frequency.
> > >>>>
> > >>>> Thanks,
> > >>>> Lijo
> > >>>
> > >>> This is a good idea. However, for now I'd like to retain the
> > >>> existing logic to
> > >> stay compatible with current parsing tools and prevent potential
> regressions.
> > >>> Also, note that "F" and "S" are optional labels, which are only
> > >>> shown for
> > >> unmatched DPM LEVEL entries.
> > >>>
> > >>
> > >> +Bill/Maisam
> > >>
> > >> What about the case when current clock matches min/max in fine
> > >> grained scenario? In the new logic, F is the label for current
> > >> clock always for fine grained clocks which is a deviation from the
> > >> old logic. Is that to always show 3 levels in fine grained?
> > >>
> > >> Thanks,
> > >> Lijo
> > >
> > >>> Is that to always show 3 levels in fine grained?
> > > yes, this part indeed works differently from the prior logic.
> > >
> > > The major problem with the current fine-grained implementation is
> > > that when the current clock does not hit min/max, the current clock is
> shown current clock at position "1" (total 3 lines output) This tends to 
> confuse
> users, who may wonder whether to use position 1 or 2 to set the maximum
> value, but 1 is expected value by driver.
> > > Therefore, this is one of the issues addressed by this patch.
> > >
> > > Back to your question: Either adopting a fixed 3-level display or
> > > retaining the old logic is reasonable ( which one is your prefer ?) The 
> > > label
> "F" stands for both fine-grained and frequency.
> > >
> >
> > I prefer the new approach to separate out current clock from the levels.
> >
> > For ex: user space sees F label, uses the value as current clock. Rest
> > of them used for level information. If it doesn't see F, try to parse
> > the legacy way.
> >
> > Alex, do you have any comments?
>
> I was never crazy about having the value in the middle be outside of the
> min/max, but IIRC, it was done that way for compatibility.
> Whatever is the least disruptive for existing tools.
>
> Alex

Hi Alex,

What do you think of this approach? We add a new label 'F' to display the 
current frequency value when fine-grain mode is enabled.
This patch fixes the below issue related to the new DPM level selection logic. 
(always print '*' to avoid this kind of issue)

https://gitlab.freedesktop.org/drm/amd/-/work_items/5295
https://gitlab.freedesktop.org/drm/amd/-/work_items/5371

Best Regards,
Kevin
>
> >
> > As a minimal representation of user space -
> >         Bill/Arif, is it possible to have this changed in amd-smi?
> >
> > Thanks,
> > Lijo
> >
> > > Best Regards,
> > > Kevin
> > >>
> > >>> Best Regards,
> > >>> Kevin
> > >>>>
> > >>>>> +
> > >>>>> +   return size;
> > >>>>>     }
> > >>>>>
> > >>>>>     int smu_cmn_print_dpm_clk_levels(struct smu_context *smu,
> > >>>>>                                struct smu_dpm_table *dpm_table,
> > >>>>>                                uint32_t cur_clk, char *buf, int 
> > >>>>> *offset)
> > >>>>>     {
> > >>>>> -   uint32_t min_clk, max_clk, level_index, count;
> > >>>>> -   uint32_t freq_values[3];
> > >>>>> -   int size, lvl, i;
> > >>>>> +   struct smu_clk_print_entry entries[SMU_MAX_DPM_LEVELS];
> > >>>>> +   uint32_t min_clk, max_clk, count, entry_count = 0;
> > >>>>> +   uint32_t selected_level = SMU_MAX_DPM_LEVELS;
> > >>>>> +   int size, i;
> > >>>>>       bool is_fine_grained;
> > >>>>>       bool is_deep_sleep;
> > >>>>> -   bool freq_match;
> > >>>>>
> > >>>>>       if (!dpm_table || !buf)
> > >>>>>               return -EINVAL;
> > >>>>>
> > >>>>> -   level_index = 0;
> > >>>>>       size = *offset;
> > >>>>> -   count = dpm_table->count;
> > >>>>>       is_fine_grained = dpm_table->flags &
> > >>>> SMU_DPM_TABLE_FINE_GRAINED;
> > >>>>> -   min_clk = SMU_DPM_TABLE_MIN(dpm_table);
> > >>>>> -   max_clk = SMU_DPM_TABLE_MAX(dpm_table);
> > >>>>> +   count = smu_cmn_get_dpm_level_count(dpm_table);
> > >>>>> +   min_clk = count ? dpm_table->dpm_levels[0].value : 0;
> > >>>>> +   max_clk = count ? dpm_table->dpm_levels[count - 1].value :
> > >>>>> + 0;
> > >>>>>
> > >>>>>       /* Deep sleep - current clock < min_clock/2, TBD: cur_clk
> > >>>>> = 0 as
> > >>>> GFXOFF */
> > >>>>>       is_deep_sleep = cur_clk < min_clk / 2;
> > >>>>> -   if (is_deep_sleep) {
> > >>>>> -           size += sysfs_emit_at(buf, size, "S: %uMhz *\n", cur_clk);
> > >>>>> -           level_index = 1;
> > >>>>> -   }
> > >>>>>
> > >>>>>       if (!is_fine_grained || count == 1) {
> > >>>>> -           for (i = 0; i < count; i++) {
> > >>>>> -                   freq_match = !is_deep_sleep &&
> > >>>>> -                                smu_cmn_freqs_match(
> > >>>>> -                                        cur_clk,
> > >>>>> -                                        
> > >>>>> dpm_table->dpm_levels[i].value);
> > >>>>> -                   size += sysfs_emit_at(buf, size, "%d: %uMhz %s\n",
> > >>>>> -                                         level_index + i,
> > >>>>> -                                         
> > >>>>> dpm_table->dpm_levels[i].value,
> > >>>>> -                                         freq_match ? "*" : "");
> > >>>>> +           if (!is_deep_sleep) {
> > >>>>> +                   selected_level =
> > >>>>> +
> > >>>>> + smu_cmn_get_closest_clk_level(dpm_table,
> > >>>> cur_clk);
> > >>>>>               }
> > >>>>> +           smu_cmn_build_discrete_levels(dpm_table, selected_level,
> > >>>>> +                                                 entries,
> > >>>>> + &entry_count);
> > >>>>>       } else {
> > >>>>> -           count = 2;
> > >>>>> -           freq_values[0] = min_clk;
> > >>>>> -           freq_values[1] = max_clk;
> > >>>>> +           smu_cmn_build_fine_grained_levels(min_clk, max_clk,
> > >>>>> +                                             entries, &entry_count);
> > >>>>> +   }
> > >>>>>
> > >>>>> -           if (!is_deep_sleep) {
> > >>>>> -                   if (smu_cmn_freqs_match(cur_clk, min_clk)) {
> > >>>>> -                           lvl = 0;
> > >>>>> -                   } else if (smu_cmn_freqs_match(cur_clk, max_clk)) 
> > >>>>> {
> > >>>>> -                           lvl = 1;
> > >>>>> -                   } else {
> > >>>>> -                           /* NOTE: use index '1' to show current 
> > >>>>> clock
> > >>>> value */
> > >>>>> -                           lvl = 1;
> > >>>>> -                           count = 3;
> > >>>>> -                           freq_values[1] = cur_clk;
> > >>>>> -                           freq_values[2] = max_clk;
> > >>>>> -                   }
> > >>>>> -           }
> > >>>>> +   size = smu_cmn_emit_clk_prefix(buf, size, is_fine_grained,
> > >>>>> +                                  is_deep_sleep, cur_clk);
> > >>>>>
> > >>>>> -           for (i = 0; i < count; i++) {
> > >>>>> -                   size += sysfs_emit_at(
> > >>>>> -                           buf, size, "%d: %uMhz %s\n", level_index 
> > >>>>> + i,
> > >>>>> -                           freq_values[i],
> > >>>>> -                           (!is_deep_sleep && i == lvl) ? "*" : "");
> > >>>>> -           }
> > >>>>> -   }
> > >>>>> +   for (i = 0; i < entry_count; i++)
> > >>>>> +           size += smu_cmn_emit_clk_line(buf, size, i,
> > >>>>> +                                        entries[i].freq,
> > >>>>> +                                        entries[i].selected);
> > >>>>>
> > >>>>>       *offset = size;
> > >>>>>
> > >>>
> > >
> >

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