From a4faff5bc496547235201bf8c2abbc94302106cd Mon Sep 17 00:00:00 2001 From: Monk Liu Date: Mon, 25 Dec 2017 15:59:30 +0800 Subject: [PATCH 3625/4131] drm/amdgpu: try again kiq access if not in IRQ(v3) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit sometimes GPU is switched to other VFs and won't swich back soon, so the kiq reg access will not signal within a short period, instead of busy waiting a long time(MAX_KEQ_REG_WAIT) and returning TMO we can istead sleep 5ms and try again later (non irq context) And since the waiting in kiq_r/weg is busy wait, so MAX_KIQ_REG_WAIT shouldn't set to a long time, set it to 10ms is more appropriate. if gpu already in reset state, don't retry the KIQ reg access otherwise it would always hang because KIQ was already die usually. v2: replace schedule() with msleep() for the wait v3: use while loop for the wait repeating use macros for the sleep period more description for it Change-Id: I088243be6ccf722f6d80c3e70c62271d37edb40d Signed-off-by: Monk Liu Reviewed-by: Christian König --- drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c | 62 ++++++++++++++++++++++++++------ 1 file changed, 52 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c index b832651..43ce2e5 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c @@ -22,7 +22,9 @@ */ #include "amdgpu.h" -#define MAX_KIQ_REG_WAIT 100000000 /* in usecs */ +#define MAX_KIQ_REG_WAIT 5000 /* in usecs, 5ms */ +#define MAX_KIQ_REG_BAILOUT_INTERVAL 5 /* in msecs, 5ms */ +#define MAX_KIQ_REG_TRY 20 uint64_t amdgpu_csa_vaddr(struct amdgpu_device *adev) { @@ -137,7 +139,7 @@ void amdgpu_virt_init_setting(struct amdgpu_device *adev) uint32_t amdgpu_virt_kiq_rreg(struct amdgpu_device *adev, uint32_t reg) { - signed long r; + signed long r, cnt = 0; unsigned long flags; uint32_t val, seq; struct amdgpu_kiq *kiq = &adev->gfx.kiq; @@ -153,18 +155,36 @@ uint32_t amdgpu_virt_kiq_rreg(struct amdgpu_device *adev, uint32_t reg) spin_unlock_irqrestore(&kiq->ring_lock, flags); r = amdgpu_fence_wait_polling(ring, seq, MAX_KIQ_REG_WAIT); - if (r < 1) { - DRM_ERROR("wait for kiq fence error: %ld\n", r); - return ~0; + + /* don't wait anymore for gpu reset case because this way may + * block gpu_recover() routine forever, e.g. this virt_kiq_rreg + * is triggered in TTM and ttm_bo_lock_delayed_workqueue() will + * never return if we keep waiting in virt_kiq_rreg, which cause + * gpu_recover() hang there. + * + * also don't wait anymore for IRQ context + * */ + if (r < 1 && (adev->in_gpu_reset || in_interrupt())) + goto failed_kiq_read; + + while (r < 1 && cnt++ < MAX_KIQ_REG_TRY) { + msleep(MAX_KIQ_REG_BAILOUT_INTERVAL); + r = amdgpu_fence_wait_polling(ring, seq, MAX_KIQ_REG_WAIT); } - val = adev->wb.wb[adev->virt.reg_val_offs]; - return val; + if (cnt > MAX_KIQ_REG_TRY) + goto failed_kiq_read; + + return adev->wb.wb[adev->virt.reg_val_offs]; + +failed_kiq_read: + pr_err("failed to read reg:%x\n", reg); + return ~0; } void amdgpu_virt_kiq_wreg(struct amdgpu_device *adev, uint32_t reg, uint32_t v) { - signed long r; + signed long r, cnt = 0; unsigned long flags; uint32_t seq; struct amdgpu_kiq *kiq = &adev->gfx.kiq; @@ -180,8 +200,30 @@ void amdgpu_virt_kiq_wreg(struct amdgpu_device *adev, uint32_t reg, uint32_t v) spin_unlock_irqrestore(&kiq->ring_lock, flags); r = amdgpu_fence_wait_polling(ring, seq, MAX_KIQ_REG_WAIT); - if (r < 1) - DRM_ERROR("wait for kiq fence error: %ld\n", r); + + /* don't wait anymore for gpu reset case because this way may + * block gpu_recover() routine forever, e.g. this virt_kiq_rreg + * is triggered in TTM and ttm_bo_lock_delayed_workqueue() will + * never return if we keep waiting in virt_kiq_rreg, which cause + * gpu_recover() hang there. + * + * also don't wait anymore for IRQ context + * */ + if (r < 1 && (adev->in_gpu_reset || in_interrupt())) + goto failed_kiq_write; + + while (r < 1 && cnt++ < MAX_KIQ_REG_TRY) { + msleep(MAX_KIQ_REG_BAILOUT_INTERVAL); + r = amdgpu_fence_wait_polling(ring, seq, MAX_KIQ_REG_WAIT); + } + + if (cnt > MAX_KIQ_REG_TRY) + goto failed_kiq_write; + + return; + +failed_kiq_write: + pr_err("failed to write reg:%x\n", reg); } /** -- 2.7.4