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Message-ID: <20251014094337.1009601-9-karunika.choo@arm.com>
Date: Tue, 14 Oct 2025 10:43:35 +0100
From: Karunika Choo <karunika.choo@....com>
To: dri-devel@...ts.freedesktop.org
Cc: nd@....com,
Boris Brezillon <boris.brezillon@...labora.com>,
Steven Price <steven.price@....com>,
Liviu Dudau <liviu.dudau@....com>,
Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
Maxime Ripard <mripard@...nel.org>,
Thomas Zimmermann <tzimmermann@...e.de>,
David Airlie <airlied@...il.com>,
Simona Vetter <simona@...ll.ch>,
linux-kernel@...r.kernel.org
Subject: [PATCH v1 08/10] drm/panthor: Support GLB_REQ.STATE field for Mali-G1 GPUs
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 <karunika.choo@....com>
---
drivers/gpu/drm/panthor/panthor_fw.c | 82 ++++++++++++++++++++++------
drivers/gpu/drm/panthor/panthor_fw.h | 7 +++
2 files changed, 73 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
index e6c39c70d348..48bbae8931cb 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 (10ULL * 1000 * 1000)
/**
* struct panthor_fw_binary_hdr - Firmware binary header.
@@ -996,6 +997,9 @@ static void panthor_fw_init_global_iface(struct panthor_device *ptdev)
GLB_IDLE_EN |
GLB_IDLE;
+ if (panthor_fw_csf_version(ptdev) >= CSF_IFACE_VERSION(4, 1, 0))
+ 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 +1073,54 @@ 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_csf_version(ptdev) >= CSF_IFACE_VERSION(4, 1, 0))
+ 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_csf_version(ptdev) >= CSF_IFACE_VERSION(4, 1, 0))
+ 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_csf_version(ptdev) >= CSF_IFACE_VERSION(4, 1, 0))
+ 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 +1137,13 @@ 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 +1171,14 @@ 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 +1216,10 @@ 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
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