From 39dc5454e33b9e76d437bef1bdc1a453a81a2fc2 Mon Sep 17 00:00:00 2001 From: Mario Kleiner Date: Tue, 29 Jul 2014 06:21:44 +0200 Subject: [PATCH] drm/radeon: Use pflip irqs for pageflip completion if possible. (v2) Skip the "manual" pageflip completion checks via polling and guessing in the vblank handler radeon_crtc_handle_vblank() on asics which are known to reliably support hw pageflip completion irqs. Those pflip irqs are a more reliable and race-free method of handling pageflip completion detection, whereas the "classic" polling method has some small races in combination with dpm on, and with the reworked pageflip implementation since Linux 3.16. On old asics without pflip irqs, the classic method is used. On asics with known good pflip irqs, only pflip irqs are used by default, but a new module parameter "use_pflipirqs" allows to override this in case we encounter asics in the wild with unreliable or faulty pflip irqs. A module parameter of 0 allows to use the classic method only in such a case. A parameter of 1 allows to use both classic method and pflip irqs as additional band-aid to avoid some small races which could happen with the classic method alone. The setting 1 gives Linux 3.16 behaviour. Hw pflip irqs are available since R600. Tested on DCE-4, AMD Cedar - FirePro 2270. v2: agd5f: only enable pflip interrupts on DCE4+ as they are not reliable on older asics. Signed-off-by: Mario Kleiner Signed-off-by: Alex Deucher --- drivers/gpu/drm/radeon/cik.c | 3 ++- drivers/gpu/drm/radeon/evergreen.c | 3 ++- drivers/gpu/drm/radeon/r600.c | 6 ++++-- drivers/gpu/drm/radeon/radeon.h | 1 + drivers/gpu/drm/radeon/radeon_display.c | 12 ++++++++++++ drivers/gpu/drm/radeon/radeon_drv.c | 4 ++++ drivers/gpu/drm/radeon/si.c | 3 ++- 7 files changed, 27 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c index 2693c57de80c..b625646bf3e2 100644 --- a/drivers/gpu/drm/radeon/cik.c +++ b/drivers/gpu/drm/radeon/cik.c @@ -7977,7 +7977,8 @@ restart_ih: case 16: /* D5 page flip */ case 18: /* D6 page flip */ DRM_DEBUG("IH: D%d flip\n", ((src_id - 8) >> 1) + 1); - radeon_crtc_handle_flip(rdev, (src_id - 8) >> 1); + if (radeon_use_pflipirq > 0) + radeon_crtc_handle_flip(rdev, (src_id - 8) >> 1); break; case 42: /* HPD hotplug */ switch (src_data) { diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c index cb2043973583..4fedd14e670a 100644 --- a/drivers/gpu/drm/radeon/evergreen.c +++ b/drivers/gpu/drm/radeon/evergreen.c @@ -4964,7 +4964,8 @@ restart_ih: case 16: /* D5 page flip */ case 18: /* D6 page flip */ DRM_DEBUG("IH: D%d flip\n", ((src_id - 8) >> 1) + 1); - radeon_crtc_handle_flip(rdev, (src_id - 8) >> 1); + if (radeon_use_pflipirq > 0) + radeon_crtc_handle_flip(rdev, (src_id - 8) >> 1); break; case 42: /* HPD hotplug */ switch (src_data) { diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c index 76e1616a25c8..c70a504d96af 100644 --- a/drivers/gpu/drm/radeon/r600.c +++ b/drivers/gpu/drm/radeon/r600.c @@ -3923,11 +3923,13 @@ restart_ih: break; case 9: /* D1 pflip */ DRM_DEBUG("IH: D1 flip\n"); - radeon_crtc_handle_flip(rdev, 0); + if (radeon_use_pflipirq > 0) + radeon_crtc_handle_flip(rdev, 0); break; case 11: /* D2 pflip */ DRM_DEBUG("IH: D2 flip\n"); - radeon_crtc_handle_flip(rdev, 1); + if (radeon_use_pflipirq > 0) + radeon_crtc_handle_flip(rdev, 1); break; case 19: /* HPD/DAC hotplug */ switch (src_data) { diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h index 142cad63c3fa..9e1732eb402c 100644 --- a/drivers/gpu/drm/radeon/radeon.h +++ b/drivers/gpu/drm/radeon/radeon.h @@ -104,6 +104,7 @@ extern int radeon_hard_reset; extern int radeon_vm_size; extern int radeon_vm_block_size; extern int radeon_deep_color; +extern int radeon_use_pflipirq; /* * Copy from radeon_drv.h so we don't have to include both and have conflicting diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c index a966074a4fba..3fdf87318069 100644 --- a/drivers/gpu/drm/radeon/radeon_display.c +++ b/drivers/gpu/drm/radeon/radeon_display.c @@ -293,6 +293,18 @@ void radeon_crtc_handle_vblank(struct radeon_device *rdev, int crtc_id) if (radeon_crtc == NULL) return; + /* Skip the pageflip completion check below (based on polling) on + * asics which reliably support hw pageflip completion irqs. pflip + * irqs are a reliable and race-free method of handling pageflip + * completion detection. A use_pflipirq module parameter < 2 allows + * to override this in case of asics with faulty pflip irqs. + * A module parameter of 0 would only use this polling based path, + * a parameter of 1 would use pflip irq only as a backup to this + * path, as in Linux 3.16. + */ + if ((radeon_use_pflipirq == 2) && ASIC_IS_DCE4(rdev)) + return; + spin_lock_irqsave(&rdev->ddev->event_lock, flags); if (radeon_crtc->flip_status != RADEON_FLIP_SUBMITTED) { DRM_DEBUG_DRIVER("radeon_crtc->flip_status = %d != " diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c index 8688e860e6a0..a773830c6c40 100644 --- a/drivers/gpu/drm/radeon/radeon_drv.c +++ b/drivers/gpu/drm/radeon/radeon_drv.c @@ -178,6 +178,7 @@ int radeon_hard_reset = 0; int radeon_vm_size = 8; int radeon_vm_block_size = -1; int radeon_deep_color = 0; +int radeon_use_pflipirq = 2; MODULE_PARM_DESC(no_wb, "Disable AGP writeback for scratch registers"); module_param_named(no_wb, radeon_no_wb, int, 0444); @@ -254,6 +255,9 @@ module_param_named(vm_block_size, radeon_vm_block_size, int, 0444); MODULE_PARM_DESC(deep_color, "Deep Color support (1 = enable, 0 = disable (default))"); module_param_named(deep_color, radeon_deep_color, int, 0444); +MODULE_PARM_DESC(use_pflipirq, "Pflip irqs for pageflip completion (0 = disable, 1 = as fallback, 2 = exclusive (default))"); +module_param_named(use_pflipirq, radeon_use_pflipirq, int, 0444); + static struct pci_device_id pciidlist[] = { radeon_PCI_IDS }; diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c index 806bed1758d6..011779bd2b3d 100644 --- a/drivers/gpu/drm/radeon/si.c +++ b/drivers/gpu/drm/radeon/si.c @@ -6531,7 +6531,8 @@ restart_ih: case 16: /* D5 page flip */ case 18: /* D6 page flip */ DRM_DEBUG("IH: D%d flip\n", ((src_id - 8) >> 1) + 1); - radeon_crtc_handle_flip(rdev, (src_id - 8) >> 1); + if (radeon_use_pflipirq > 0) + radeon_crtc_handle_flip(rdev, (src_id - 8) >> 1); break; case 42: /* HPD hotplug */ switch (src_data) { -- 2.34.1