From 320662381ca243a3364663e917a7447afaf618fa Mon Sep 17 00:00:00 2001 From: Vinay Belgaumkar Date: Wed, 16 Sep 2026 12:06:14 -0700 Subject: [PATCH] drm/xe: Poll GT for C6 before D3 Ensure GT C6 state before D3 transition in runtime suspend flow. This avoids the scenario where GT is being accessed after D3 state is programmed. If the check for C6 fails, resume the device so it is not stuck in an intermediate state. v2: Force resume when we cancel suspend due to C6 check (Sashiko) v3: Abort the suspend properly when idle check fails (Sashiko) v4: Only check for C6 during suspend (Rodrigo). Have check in xe_pci_runtime_suspend() instead of xe_pci_suspend(). v5: Don't checkfor PVC (Sashiko), rename function from_device_c6 to _device_idle v6: Rename to _wait_all_c6 and move PVC check to gt_idle (Rodrigo) Cc: Badal Nilawar Cc: Rodrigo Vivi Signed-off-by: Vinay Belgaumkar Reviewed-by: Rodrigo Vivi Link: https://patch.msgid.link/20260916190614.3047807-1-vinay.belgaumkar@intel.com Signed-off-by: Rodrigo Vivi --- drivers/gpu/drm/xe/xe_gt_idle.c | 39 +++++++++++++++++++++++++++++++++ drivers/gpu/drm/xe/xe_gt_idle.h | 1 + drivers/gpu/drm/xe/xe_pci.c | 13 ++++++++++- drivers/gpu/drm/xe/xe_pm.c | 18 +++++++++++++++ drivers/gpu/drm/xe/xe_pm.h | 1 + 5 files changed, 71 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/xe/xe_gt_idle.c b/drivers/gpu/drm/xe/xe_gt_idle.c index c208d7563e36..2eefd62f8d59 100644 --- a/drivers/gpu/drm/xe/xe_gt_idle.c +++ b/drivers/gpu/drm/xe/xe_gt_idle.c @@ -8,10 +8,12 @@ #include #include +#include #include "xe_force_wake.h" #include "xe_device.h" #include "xe_gt.h" #include "xe_gt_idle.h" +#include "xe_gt_printk.h" #include "xe_gt_sysfs.h" #include "xe_guc_pc.h" #include "regs/xe_gt_regs.h" @@ -451,3 +453,40 @@ int xe_gt_idle_disable_c6(struct xe_gt *gt) return 0; } + +static int wait_for_gt_c6_state(struct xe_gt *gt, u32 timeout_ms) +{ + struct xe_guc_pc *pc = >->uc.guc.pc; + enum xe_gt_idle_state state; + + return poll_timeout_us(state = gt->gtidle.idle_status(pc), + state == GT_IDLE_C6, + 20, + timeout_ms * USEC_PER_MSEC, + false); +} + +/** + * xe_gt_idle_wait_for_c6 - Poll for GT C6 + * @gt: GT object + * @timeout_ms: wait time in ms + * + * This function waits for GT to enter C6. + * + * Return: 0 on success, -EAGAIN otherwise + */ +int xe_gt_idle_wait_for_c6(struct xe_gt *gt, u32 timeout_ms) +{ + if (IS_SRIOV_VF(gt_to_xe(gt))) + return 0; + + if (gt_to_xe(gt)->info.platform == XE_PVC) + return 0; + + if (wait_for_gt_c6_state(gt, timeout_ms)) { + xe_gt_dbg(gt, "GT is not in C6\n"); + return -EAGAIN; + } + + return 0; +} diff --git a/drivers/gpu/drm/xe/xe_gt_idle.h b/drivers/gpu/drm/xe/xe_gt_idle.h index 9c34a155e102..2c8e9adf4a68 100644 --- a/drivers/gpu/drm/xe/xe_gt_idle.h +++ b/drivers/gpu/drm/xe/xe_gt_idle.h @@ -18,5 +18,6 @@ void xe_gt_idle_enable_pg(struct xe_gt *gt); void xe_gt_idle_disable_pg(struct xe_gt *gt); int xe_gt_idle_pg_print(struct xe_gt *gt, struct drm_printer *p); u64 xe_gt_idle_residency_msec(struct xe_gt_idle *gtidle); +int xe_gt_idle_wait_for_c6(struct xe_gt *gt, u32 timeout_ms); #endif /* _XE_GT_IDLE_H_ */ diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c index 00b2b5dfb8f6..d66d5a0339ae 100644 --- a/drivers/gpu/drm/xe/xe_pci.c +++ b/drivers/gpu/drm/xe/xe_pci.c @@ -1379,7 +1379,7 @@ static int xe_pci_runtime_suspend(struct device *dev) { struct pci_dev *pdev = to_pci_dev(dev); struct xe_device *xe = pdev_to_xe_device(pdev); - int err; + int err, ret; /* * We hold an additional reference to the runtime PM to keep PF in D0 @@ -1394,6 +1394,17 @@ static int xe_pci_runtime_suspend(struct device *dev) if (err) return err; + err = xe_pm_wait_all_c6(xe); + if (err) { + drm_dbg(&xe->drm, "Resuming - GT C6 check failed!"); + ret = xe_pm_runtime_resume(xe); + if (ret) { + drm_err(&xe->drm, "Resume failed after suspend was canceled"); + return ret; + } + return err; + } + pci_save_state(pdev); if (xe->d3cold.allowed) { diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c index f517bf453b54..4a745c3a933b 100644 --- a/drivers/gpu/drm/xe/xe_pm.c +++ b/drivers/gpu/drm/xe/xe_pm.c @@ -1030,6 +1030,24 @@ void xe_pm_d3cold_allowed_toggle(struct xe_device *xe) mutex_unlock(&xe->d3cold.lock); } +/** + * xe_pm_wait_all_c6() - Wait for all GTs to enter C6. + * @xe: xe device instance + * + * Return: 0 on success, -EAGAIN on failure + */ +int xe_pm_wait_all_c6(struct xe_device *xe) +{ + struct xe_gt *gt; + u8 id; + + for_each_gt(gt, xe, id) + if (xe_gt_idle_wait_for_c6(gt, 200)) + return -EAGAIN; + + return 0; +} + /** * xe_pm_module_init() - Perform xe_pm specific module initialization. * diff --git a/drivers/gpu/drm/xe/xe_pm.h b/drivers/gpu/drm/xe/xe_pm.h index 6d5ab09cb769..fd8b2eab5de9 100644 --- a/drivers/gpu/drm/xe/xe_pm.h +++ b/drivers/gpu/drm/xe/xe_pm.h @@ -36,6 +36,7 @@ void xe_pm_d3cold_allowed_toggle(struct xe_device *xe); bool xe_rpm_reclaim_safe(const struct xe_device *xe); struct task_struct *xe_pm_read_callback_task(struct xe_device *xe); int xe_pm_block_on_suspend(struct xe_device *xe); +int xe_pm_wait_all_c6(struct xe_device *xe); void xe_pm_might_block_on_suspend(void); int xe_pm_module_init(void);