Re: [PATCH v2 2/2] drm/panthor: add custom ASN_HASH support for mt8196

Steven Price
2025-09-29T15:44:24Z

On 13/09/2025 01:21, Chia-I Wu wrote:
> Add panthor_soc_data to control custom ASN_HASH. Add compatible string
> for "mediatek,mt8196-mali" and enable custom ASN_HASH for the soc.
>
> Without custom ASN_HASH, FW fails to boot
>
> panthor 48000000.gpu: [drm] *ERROR* Unhandled Page fault in AS0 at VA 0x0000000000000000
> panthor 48000000.gpu: [drm] *ERROR* Failed to boot MCU (status=fatal)
> panthor 48000000.gpu: probe with driver panthor failed with error -110
>
> With custom ASN_HASH, panthor probes fine and userspace boots to ui just
> fine as well
>
> panthor 48000000.gpu: [drm] clock rate = 0
> panthor 48000000.gpu: EM: created perf domain
> panthor 48000000.gpu: [drm] Mali-G925-Immortalis id 0xd830 major 0x0 minor 0x1 status 0x5
> panthor 48000000.gpu: [drm] Features: L2:0x8130306 Tiler:0x809 Mem:0x301 MMU:0x2830 AS:0xff
> panthor 48000000.gpu: [drm] shader_present=0xee0077 l2_present=0x1 tiler_present=0x1
> panthor 48000000.gpu: [drm] Firmware protected mode entry not be supported, ignoring
> panthor 48000000.gpu: [drm] Firmware git sha: 27713280172c742d467a4b7d11180930094092ec
> panthor 48000000.gpu: [drm] CSF FW using interface v3.13.0, Features 0x10 Instrumentation features 0x71
> [drm] Initialized panthor 1.5.0 for 48000000.gpu on minor 1
>
> Note that the clock and the regulator drivers are not upstreamed yet.
> They might as well take a different form when upstreamed.
>
> Signed-off-by: Chia-I Wu <olvaffe@gmail.com>

Reviewed-by: Steven Price <steven.price@arm.com>

>
> ---
> v2:
> - remove CONFIG_DRM_PANTHOR_SOC_MT8196 and panthor_soc*.[ch]
> - update commit message
> ---
> drivers/gpu/drm/panthor/panthor_device.c | 2 ++
> drivers/gpu/drm/panthor/panthor_device.h | 14 +++++++++++++
> drivers/gpu/drm/panthor/panthor_drv.c | 6 ++++++
> drivers/gpu/drm/panthor/panthor_gpu.c | 25 +++++++++++++++++++++++-
> drivers/gpu/drm/panthor/panthor_regs.h | 4 ++++
> 5 files changed, 50 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
> index 81df49880bd87..c7033d82cef55 100644
> --- a/drivers/gpu/drm/panthor/panthor_device.c
> +++ b/drivers/gpu/drm/panthor/panthor_device.c
> @@ -172,6 +172,8 @@ int panthor_device_init(struct panthor_device *ptdev)
> struct page *p;
> int ret;
>
> + ptdev->soc_data = of_device_get_match_data(ptdev->base.dev);
> +
> init_completion(&ptdev->unplug.done);
> ret = drmm_mutex_init(&ptdev->base, &ptdev->unplug.lock);
> if (ret)
> diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
> index 4fc7cf2aeed57..9f0649ecfc4fc 100644
> --- a/drivers/gpu/drm/panthor/panthor_device.h
> +++ b/drivers/gpu/drm/panthor/panthor_device.h
> @@ -31,6 +31,17 @@ struct panthor_perfcnt;
> struct panthor_vm;
> struct panthor_vm_pool;
>
> +/**
> + * struct panthor_soc_data - Panthor SoC Data
> + */
> +struct panthor_soc_data {
> + /** @asn_hash_enable: True if GPU_L2_CONFIG_ASN_HASH_ENABLE must be set. */
> + bool asn_hash_enable;
> +
> + /** @asn_hash: ASN_HASH values when asn_hash_enable is true. */
> + u32 asn_hash[3];
> +};
> +
> /**
> * enum panthor_device_pm_state - PM state
> */
> @@ -93,6 +104,9 @@ struct panthor_device {
> /** @base: Base drm_device. */
> struct drm_device base;
>
> + /** @soc_data: Optional SoC data. */
> + const struct panthor_soc_data *soc_data;
> +
> /** @phys_addr: Physical address of the iomem region. */
> phys_addr_t phys_addr;
>
> diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
> index be962b1387f03..9dd90754865ac 100644
> --- a/drivers/gpu/drm/panthor/panthor_drv.c
> +++ b/drivers/gpu/drm/panthor/panthor_drv.c
> @@ -1682,7 +1682,13 @@ static struct attribute *panthor_attrs[] = {
>
> ATTRIBUTE_GROUPS(panthor);
>
> +static const struct panthor_soc_data soc_data_mediatek_mt8196 = {
> + .asn_hash_enable = true,
> + .asn_hash = { 0xb, 0xe, 0x0, },
> +};
> +
> static const struct of_device_id dt_match[] = {
> + { .compatible = "mediatek,mt8196-mali", .data = &soc_data_mediatek_mt8196, },
> { .compatible = "rockchip,rk3588-mali" },
> { .compatible = "arm,mali-valhall-csf" },
> {}
> diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c
> index db69449a5be09..9d98720ce03fd 100644
> --- a/drivers/gpu/drm/panthor/panthor_gpu.c
> +++ b/drivers/gpu/drm/panthor/panthor_gpu.c
> @@ -52,6 +52,28 @@ static void panthor_gpu_coherency_set(struct panthor_device *ptdev)
> ptdev->coherent ? GPU_COHERENCY_PROT_BIT(ACE_LITE) : GPU_COHERENCY_NONE);
> }
>
> +static void panthor_gpu_l2_config_set(struct panthor_device *ptdev)
> +{
> + const struct panthor_soc_data *data = ptdev->soc_data;
> + u32 l2_config;
> + u32 i;
> +
> + if (!data || !data->asn_hash_enable)
> + return;
> +
> + if (GPU_ARCH_MAJOR(ptdev->gpu_info.gpu_id) < 11) {
> + drm_err(&ptdev->base, "Custom ASN hash not supported by the device");
> + return;
> + }
> +
> + for (i = 0; i < ARRAY_SIZE(data->asn_hash); i++)
> + gpu_write(ptdev, GPU_ASN_HASH(i), data->asn_hash[i]);
> +
> + l2_config = gpu_read(ptdev, GPU_L2_CONFIG);
> + l2_config |= GPU_L2_CONFIG_ASN_HASH_ENABLE;
> + gpu_write(ptdev, GPU_L2_CONFIG, l2_config);
> +}
> +
> static void panthor_gpu_irq_handler(struct panthor_device *ptdev, u32 status)
> {
> gpu_write(ptdev, GPU_INT_CLEAR, status);
> @@ -241,8 +263,9 @@ int panthor_gpu_l2_power_on(struct panthor_device *ptdev)
> hweight64(ptdev->gpu_info.shader_present));
> }
>
> - /* Set the desired coherency mode before the power up of L2 */
> + /* Set the desired coherency mode and L2 config before the power up of L2 */
> panthor_gpu_coherency_set(ptdev);
> + panthor_gpu_l2_config_set(ptdev);
>
> return panthor_gpu_power_on(ptdev, L2, 1, 20000);
> }
> diff --git a/drivers/gpu/drm/panthor/panthor_regs.h b/drivers/gpu/drm/panthor/panthor_regs.h
> index 8bee76d01bf83..8fa69f33e911e 100644
> --- a/drivers/gpu/drm/panthor/panthor_regs.h
> +++ b/drivers/gpu/drm/panthor/panthor_regs.h
> @@ -64,6 +64,8 @@
>
> #define GPU_FAULT_STATUS 0x3C
> #define GPU_FAULT_ADDR 0x40
> +#define GPU_L2_CONFIG 0x48
> +#define GPU_L2_CONFIG_ASN_HASH_ENABLE BIT(24)
>
> #define GPU_PWR_KEY 0x50
> #define GPU_PWR_KEY_UNLOCK 0x2968A819
> @@ -110,6 +112,8 @@
>
> #define GPU_REVID 0x280
>
> +#define GPU_ASN_HASH(n) (0x2C0 + ((n) * 4))
> +
> #define GPU_COHERENCY_FEATURES 0x300
> #define GPU_COHERENCY_PROT_BIT(name) BIT(GPU_COHERENCY_ ## name)
>