On 27/10/2025 16:13, Karunika Choo wrote: > Add support for the GLB_REQ.STATE field introduced in CSF v4.1+, which > replaces the HALT bit to provide finer control over the MCU state. This > change implements basic handling for transitioning the MCU between > ACTIVE and HALT states on Mali-G1 GPUs. > > The update introduces new helpers to issue the state change requests, > poll for MCU halt completion, and restore the MCU to an active state > after halting. > > Signed-off-by: Karunika Choo <[email protected]>
Reviewed-by: Steven Price <[email protected]> > --- > v3: > * Fixed missed CSF_IFACE_VERSION check with pathor_fw_has_glb_state(). > v2: > * Reduced MCU_HALT_TIMEOUT_US to 1 second. > * Wrap the CSG_IFACE_VERSION checks for v4.1.0 with > panthor_fw_has_glb_state(). > * Removed use of undefined panthor_fw_csf_version() MACRO. > --- > drivers/gpu/drm/panthor/panthor_fw.c | 89 +++++++++++++++++++++++----- > drivers/gpu/drm/panthor/panthor_fw.h | 7 +++ > 2 files changed, 80 insertions(+), 16 deletions(-) > > diff --git a/drivers/gpu/drm/panthor/panthor_fw.c > b/drivers/gpu/drm/panthor/panthor_fw.c > index e6c39c70d348..fb1f69ef76fb 100644 > --- a/drivers/gpu/drm/panthor/panthor_fw.c > +++ b/drivers/gpu/drm/panthor/panthor_fw.c > @@ -33,6 +33,7 @@ > #define PROGRESS_TIMEOUT_SCALE_SHIFT 10 > #define IDLE_HYSTERESIS_US 800 > #define PWROFF_HYSTERESIS_US 10000 > +#define MCU_HALT_TIMEOUT_US (1ULL * USEC_PER_SEC) > > /** > * struct panthor_fw_binary_hdr - Firmware binary header. > @@ -317,6 +318,13 @@ panthor_fw_get_cs_iface(struct panthor_device *ptdev, > u32 csg_slot, u32 cs_slot) > return &ptdev->fw->iface.streams[csg_slot][cs_slot]; > } > > +static bool panthor_fw_has_glb_state(struct panthor_device *ptdev) > +{ > + struct panthor_fw_global_iface *glb_iface = > panthor_fw_get_glb_iface(ptdev); > + > + return glb_iface->control->version >= CSF_IFACE_VERSION(4, 1, 0); > +} > + > /** > * panthor_fw_conv_timeout() - Convert a timeout into a cycle-count > * @ptdev: Device. > @@ -996,6 +1004,9 @@ static void panthor_fw_init_global_iface(struct > panthor_device *ptdev) > GLB_IDLE_EN | > GLB_IDLE; > > + if (panthor_fw_has_glb_state(ptdev)) > + glb_iface->input->ack_irq_mask |= GLB_STATE_MASK; > + > panthor_fw_update_reqs(glb_iface, req, GLB_IDLE_EN, GLB_IDLE_EN); > panthor_fw_toggle_reqs(glb_iface, req, ack, > GLB_CFG_ALLOC_EN | > @@ -1069,6 +1080,54 @@ static void panthor_fw_stop(struct panthor_device > *ptdev) > drm_err(&ptdev->base, "Failed to stop MCU"); > } > > +static bool panthor_fw_mcu_halted(struct panthor_device *ptdev) > +{ > + struct panthor_fw_global_iface *glb_iface = > panthor_fw_get_glb_iface(ptdev); > + bool halted; > + > + halted = gpu_read(ptdev, MCU_STATUS) == MCU_STATUS_HALT; > + > + if (panthor_fw_has_glb_state(ptdev)) > + halted &= (GLB_STATE_GET(glb_iface->output->ack) == > GLB_STATE_HALT); > + > + return halted; > +} > + > +static void panthor_fw_halt_mcu(struct panthor_device *ptdev) > +{ > + struct panthor_fw_global_iface *glb_iface = > panthor_fw_get_glb_iface(ptdev); > + > + if (panthor_fw_has_glb_state(ptdev)) > + panthor_fw_update_reqs(glb_iface, req, > GLB_STATE(GLB_STATE_HALT), GLB_STATE_MASK); > + else > + panthor_fw_update_reqs(glb_iface, req, GLB_HALT, GLB_HALT); > + > + gpu_write(ptdev, CSF_DOORBELL(CSF_GLB_DOORBELL_ID), 1); > +} > + > +static bool panthor_fw_wait_mcu_halted(struct panthor_device *ptdev) > +{ > + bool halted = false; > + > + if (read_poll_timeout_atomic(panthor_fw_mcu_halted, halted, halted, 10, > + MCU_HALT_TIMEOUT_US, 0, ptdev)) { > + drm_warn(&ptdev->base, "Timed out waiting for MCU to halt"); > + return false; > + } > + > + return true; > +} > + > +static void panthor_fw_mcu_set_active(struct panthor_device *ptdev) > +{ > + struct panthor_fw_global_iface *glb_iface = > panthor_fw_get_glb_iface(ptdev); > + > + if (panthor_fw_has_glb_state(ptdev)) > + panthor_fw_update_reqs(glb_iface, req, > GLB_STATE(GLB_STATE_ACTIVE), GLB_STATE_MASK); > + else > + panthor_fw_update_reqs(glb_iface, req, 0, GLB_HALT); > +} > + > /** > * panthor_fw_pre_reset() - Call before a reset. > * @ptdev: Device. > @@ -1085,19 +1144,13 @@ void panthor_fw_pre_reset(struct panthor_device > *ptdev, bool on_hang) > ptdev->reset.fast = false; > > if (!on_hang) { > - struct panthor_fw_global_iface *glb_iface = > panthor_fw_get_glb_iface(ptdev); > - u32 status; > - > - panthor_fw_update_reqs(glb_iface, req, GLB_HALT, GLB_HALT); > - gpu_write(ptdev, CSF_DOORBELL(CSF_GLB_DOORBELL_ID), 1); > - if (!gpu_read_poll_timeout(ptdev, MCU_STATUS, status, > - status == MCU_STATUS_HALT, 10, > - 100000)) { > - ptdev->reset.fast = true; > - } else { > + panthor_fw_halt_mcu(ptdev); > + if (!panthor_fw_wait_mcu_halted(ptdev)) > drm_warn(&ptdev->base, "Failed to cleanly suspend MCU"); > - } > + else > + ptdev->reset.fast = true; > } > + panthor_fw_stop(ptdev); > > panthor_job_irq_suspend(&ptdev->fw->irq); > } > @@ -1125,14 +1178,14 @@ int panthor_fw_post_reset(struct panthor_device > *ptdev) > */ > panthor_reload_fw_sections(ptdev, true); > } else { > - /* The FW detects 0 -> 1 transitions. Make sure we reset > - * the HALT bit before the FW is rebooted. > + /* > + * If the FW was previously successfully halted in the pre-reset > + * operation, we need to transition it to active again before > + * the FW is rebooted. > * This is not needed on a slow reset because FW sections are > * re-initialized. > */ > - struct panthor_fw_global_iface *glb_iface = > panthor_fw_get_glb_iface(ptdev); > - > - panthor_fw_update_reqs(glb_iface, req, 0, GLB_HALT); > + panthor_fw_mcu_set_active(ptdev); > } > > ret = panthor_fw_start(ptdev); > @@ -1170,6 +1223,10 @@ void panthor_fw_unplug(struct panthor_device *ptdev) > if (ptdev->fw->irq.irq) > panthor_job_irq_suspend(&ptdev->fw->irq); > > + panthor_fw_halt_mcu(ptdev); > + if (!panthor_fw_wait_mcu_halted(ptdev)) > + drm_warn(&ptdev->base, "Failed to halt MCU on unplug"); > + > panthor_fw_stop(ptdev); > } > > diff --git a/drivers/gpu/drm/panthor/panthor_fw.h > b/drivers/gpu/drm/panthor/panthor_fw.h > index 6598d96c6d2a..a19ed48b2d0b 100644 > --- a/drivers/gpu/drm/panthor/panthor_fw.h > +++ b/drivers/gpu/drm/panthor/panthor_fw.h > @@ -214,6 +214,13 @@ struct panthor_fw_global_input_iface { > #define GLB_FWCFG_UPDATE BIT(9) > #define GLB_IDLE_EN BIT(10) > #define GLB_SLEEP BIT(12) > +#define GLB_STATE_MASK GENMASK(14, 12) > +#define GLB_STATE_ACTIVE 0 > +#define GLB_STATE_HALT 1 > +#define GLB_STATE_SLEEP 2 > +#define GLB_STATE_SUSPEND 3 > +#define GLB_STATE(x) (((x) << 12) & > GLB_STATE_MASK) > +#define GLB_STATE_GET(x) (((x) & GLB_STATE_MASK) >> 12) > #define GLB_INACTIVE_COMPUTE BIT(20) > #define GLB_INACTIVE_FRAGMENT BIT(21) > #define GLB_INACTIVE_TILER BIT(22) > -- > 2.49.0 >
