Re: [PATCH v2 15/16] drm/msm/a6xx: Enable IFPC on Adreno X1-85

[Akhil P Oommen <akhilpo@oss.qualcomm.com>]

On 11/1/2025 6:27 PM, Rob Clark wrote:
> On Fri, Oct 31, 2025 at 4:43 PM Chia-I Wu <olvaffe@gmail.com> wrote:
>>
>> On Mon, Sep 8, 2025 at 1:28 AM Akhil P Oommen <akhilpo@oss.qualcomm.com> wrote:
>>>
>>> Add the IFPC restore register list and enable IFPC support on Adreno
>>> X1-85 gpu.
>>>
>>> Signed-off-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
>>> ---
>>>  drivers/gpu/drm/msm/adreno/a6xx_catalog.c | 68 ++++++++++++++++++++++++++++++-
>>>  drivers/gpu/drm/msm/adreno/a6xx_gpu.c     | 15 +++++--
>>>  drivers/gpu/drm/msm/adreno/a6xx_gpu.h     |  1 +
>>>  3 files changed, 79 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
>>> index 00e1afd46b81546eec03e22cda9e9a604f6f3b60..547c046730a9b50a82cc9b27f08a5b1eeb08dced 100644
>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
>>> @@ -1343,6 +1343,69 @@ static const uint32_t a7xx_pwrup_reglist_regs[] = {
>>>
>>>  DECLARE_ADRENO_REGLIST_LIST(a7xx_pwrup_reglist);
>>>
>>> +/* Applicable for X185, A750 */
>>> +static const u32 a750_ifpc_reglist_regs[] = {
>>> +       REG_A6XX_TPL1_BICUBIC_WEIGHTS_TABLE_0,
>>> +       REG_A6XX_TPL1_BICUBIC_WEIGHTS_TABLE_1,
>>> +       REG_A6XX_TPL1_BICUBIC_WEIGHTS_TABLE_2,
>>> +       REG_A6XX_TPL1_BICUBIC_WEIGHTS_TABLE_3,
>>> +       REG_A6XX_TPL1_BICUBIC_WEIGHTS_TABLE_4,
>>> +       REG_A6XX_TPL1_NC_MODE_CNTL,
>>> +       REG_A6XX_SP_NC_MODE_CNTL,
>>> +       REG_A6XX_CP_DBG_ECO_CNTL,
>>> +       REG_A6XX_CP_PROTECT_CNTL,
>>> +       REG_A6XX_CP_PROTECT(0),
>>> +       REG_A6XX_CP_PROTECT(1),
>>> +       REG_A6XX_CP_PROTECT(2),
>>> +       REG_A6XX_CP_PROTECT(3),
>>> +       REG_A6XX_CP_PROTECT(4),
>>> +       REG_A6XX_CP_PROTECT(5),
>>> +       REG_A6XX_CP_PROTECT(6),
>>> +       REG_A6XX_CP_PROTECT(7),
>>> +       REG_A6XX_CP_PROTECT(8),
>>> +       REG_A6XX_CP_PROTECT(9),
>>> +       REG_A6XX_CP_PROTECT(10),
>>> +       REG_A6XX_CP_PROTECT(11),
>>> +       REG_A6XX_CP_PROTECT(12),
>>> +       REG_A6XX_CP_PROTECT(13),
>>> +       REG_A6XX_CP_PROTECT(14),
>>> +       REG_A6XX_CP_PROTECT(15),
>>> +       REG_A6XX_CP_PROTECT(16),
>>> +       REG_A6XX_CP_PROTECT(17),
>>> +       REG_A6XX_CP_PROTECT(18),
>>> +       REG_A6XX_CP_PROTECT(19),
>>> +       REG_A6XX_CP_PROTECT(20),
>>> +       REG_A6XX_CP_PROTECT(21),
>>> +       REG_A6XX_CP_PROTECT(22),
>>> +       REG_A6XX_CP_PROTECT(23),
>>> +       REG_A6XX_CP_PROTECT(24),
>>> +       REG_A6XX_CP_PROTECT(25),
>>> +       REG_A6XX_CP_PROTECT(26),
>>> +       REG_A6XX_CP_PROTECT(27),
>>> +       REG_A6XX_CP_PROTECT(28),
>>> +       REG_A6XX_CP_PROTECT(29),
>>> +       REG_A6XX_CP_PROTECT(30),
>>> +       REG_A6XX_CP_PROTECT(31),
>>> +       REG_A6XX_CP_PROTECT(32),
>>> +       REG_A6XX_CP_PROTECT(33),
>>> +       REG_A6XX_CP_PROTECT(34),
>>> +       REG_A6XX_CP_PROTECT(35),
>>> +       REG_A6XX_CP_PROTECT(36),
>>> +       REG_A6XX_CP_PROTECT(37),
>>> +       REG_A6XX_CP_PROTECT(38),
>>> +       REG_A6XX_CP_PROTECT(39),
>>> +       REG_A6XX_CP_PROTECT(40),
>>> +       REG_A6XX_CP_PROTECT(41),
>>> +       REG_A6XX_CP_PROTECT(42),
>>> +       REG_A6XX_CP_PROTECT(43),
>>> +       REG_A6XX_CP_PROTECT(44),
>>> +       REG_A6XX_CP_PROTECT(45),
>>> +       REG_A6XX_CP_PROTECT(46),
>>> +       REG_A6XX_CP_PROTECT(47),
>>> +};
>>> +
>>> +DECLARE_ADRENO_REGLIST_LIST(a750_ifpc_reglist);
>>> +
>>>  static const struct adreno_info a7xx_gpus[] = {
>>>         {
>>>                 .chip_ids = ADRENO_CHIP_IDS(0x07000200),
>>> @@ -1432,12 +1495,14 @@ static const struct adreno_info a7xx_gpus[] = {
>>>                 .inactive_period = DRM_MSM_INACTIVE_PERIOD,
>>>                 .quirks = ADRENO_QUIRK_HAS_CACHED_COHERENT |
>>>                           ADRENO_QUIRK_HAS_HW_APRIV |
>>> -                         ADRENO_QUIRK_PREEMPTION,
>>> +                         ADRENO_QUIRK_PREEMPTION |
>>> +                         ADRENO_QUIRK_IFPC,
>>>                 .init = a6xx_gpu_init,
>>>                 .a6xx = &(const struct a6xx_info) {
>>>                         .hwcg = a740_hwcg,
>>>                         .protect = &a730_protect,
>>>                         .pwrup_reglist = &a7xx_pwrup_reglist,
>>> +                       .ifpc_reglist = &a750_ifpc_reglist,
>>>                         .gmu_chipid = 0x7050001,
>>>                         .gmu_cgc_mode = 0x00020202,
>>>                 },
>>> @@ -1466,6 +1531,7 @@ static const struct adreno_info a7xx_gpus[] = {
>>>                 .a6xx = &(const struct a6xx_info) {
>>>                         .protect = &a730_protect,
>>>                         .pwrup_reglist = &a7xx_pwrup_reglist,
>>> +                       .ifpc_reglist = &a750_ifpc_reglist,
>>>                         .gmu_chipid = 0x7090100,
>>>                         .gmu_cgc_mode = 0x00020202,
>>>                         .bcms = (const struct a6xx_bcm[]) {
>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
>>> index 76dd78f5c48ea818a2aa209e0c0c88bc5e8f4e06..91a2a82c4f388ca6b052172efdd7255165f3c04a 100644
>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
>>> @@ -828,11 +828,10 @@ static void a7xx_patch_pwrup_reglist(struct msm_gpu *gpu)
>>>         u32 *dest = (u32 *)&lock->regs[0];
>>>         int i;
>>>
>>> -       reglist = adreno_gpu->info->a6xx->pwrup_reglist;
>>> -
>>>         lock->gpu_req = lock->cpu_req = lock->turn = 0;
>>> -       lock->ifpc_list_len = 0;
>>> -       lock->preemption_list_len = reglist->count;
>>> +
>>> +       reglist = adreno_gpu->info->a6xx->ifpc_reglist;
>> This is NULL on X1-45 and causes
>>
>>   [    8.795603] Unable to handle kernel NULL pointer dereference at
>> virtual address 0000000000000008
> 
> Hmm, this is probably going to happen on all a7xx which don't have
> IFPC from the looks of it.
> 
> We should either check for the IFPC quirk.. or maybe just drop the
> quirk and decide whether IFPC is supported based on ifpc_reglist !=
> NULL?
> 
> (That said, we probably do want to have IFPC enabled for x1-45)

We should add a check for IFPC quirk here. Chia, do you plan to send a fix?

To enable IFPC, we can just add a750_ifpc_reglist_regs[] to
adreno_gpu->info->a6xx->ifpc_reglist and enable the IFPC quirk.

-Akhil.

> 
> BR,
> -R
> 
>>> +       lock->ifpc_list_len = reglist->count;
>>>
>>>         /*
>>>          * For each entry in each of the lists, write the offset and the current
>>> @@ -843,6 +842,14 @@ static void a7xx_patch_pwrup_reglist(struct msm_gpu *gpu)
>>>                 *dest++ = gpu_read(gpu, reglist->regs[i]);
>>>         }
>>>
>>> +       reglist = adreno_gpu->info->a6xx->pwrup_reglist;
>>> +       lock->preemption_list_len = reglist->count;
>>> +
>>> +       for (i = 0; i < reglist->count; i++) {
>>> +               *dest++ = reglist->regs[i];
>>> +               *dest++ = gpu_read(gpu, reglist->regs[i]);
>>> +       }
>>> +
>>>         /*
>>>          * The overall register list is composed of
>>>          * 1. Static IFPC-only registers
>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.h b/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
>>> index 124c63c4615930b00c64e488a498163ae35afccd..0b17d36c36a9567e6afa4269ae7783ed3578e40e 100644
>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
>>> @@ -45,6 +45,7 @@ struct a6xx_info {
>>>         const struct adreno_reglist *hwcg;
>>>         const struct adreno_protect *protect;
>>>         const struct adreno_reglist_list *pwrup_reglist;
>>> +       const struct adreno_reglist_list *ifpc_reglist;
>>>         u32 gmu_chipid;
>>>         u32 gmu_cgc_mode;
>>>         u32 prim_fifo_threshold;
>>>
>>> --
>>> 2.50.1
>>>