This patch simplifying the handling of modeset locks and atomic state for an atomic commit is based on https://lore.kernel.org/all/20210715184954.7794-2-ville.syrjala@xxxxxxxxxxxxxxx/ adding the helper to i915. I find this approach preferrable than open-coding the corresponding steps (fixed for me an atomic state reset during a DEADLK retry, which I missed in the open-coded version) and also better than the existing DRM_MODESET_LOCK_ALL_BEGIN/END macros for the reasons described in the above original patchset. This change takes the helper into use only for atomic commits during DDI hotplug handling, as a preparation for a follow-up patch adding a similar commit started from the same spot. Other places doing a driver-internal atomic commit is to be converted by a follow-up patchset. Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> --- drivers/gpu/drm/i915/Makefile | 1 + drivers/gpu/drm/i915/display/intel_ddi.c | 17 ++----- .../gpu/drm/i915/display/intel_modeset_lock.c | 50 +++++++++++++++++++ .../gpu/drm/i915/display/intel_modeset_lock.h | 33 ++++++++++++ 4 files changed, 87 insertions(+), 14 deletions(-) create mode 100644 drivers/gpu/drm/i915/display/intel_modeset_lock.c create mode 100644 drivers/gpu/drm/i915/display/intel_modeset_lock.h diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index 9af76e376ca91..ef6feb2aad2ad 100644 --- a/drivers/gpu/drm/i915/Makefile +++ b/drivers/gpu/drm/i915/Makefile @@ -263,6 +263,7 @@ i915-y += \ display/intel_hti.o \ display/intel_load_detect.o \ display/intel_lpe_audio.o \ + display/intel_modeset_lock.o \ display/intel_modeset_verify.o \ display/intel_modeset_setup.o \ display/intel_overlay.o \ diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c index 55f36d9d509c6..eb391fff0f1be 100644 --- a/drivers/gpu/drm/i915/display/intel_ddi.c +++ b/drivers/gpu/drm/i915/display/intel_ddi.c @@ -63,6 +63,7 @@ #include "intel_hti.h" #include "intel_lspcon.h" #include "intel_mg_phy_regs.h" +#include "intel_modeset_lock.h" #include "intel_pps.h" #include "intel_psr.h" #include "intel_quirks.h" @@ -4400,26 +4401,14 @@ intel_ddi_hotplug(struct intel_encoder *encoder, state = intel_encoder_hotplug(encoder, connector); - drm_modeset_acquire_init(&ctx, 0); - - for (;;) { + intel_modeset_lock_ctx_retry(&ctx, NULL, 0, ret) { if (connector->base.connector_type == DRM_MODE_CONNECTOR_HDMIA) ret = intel_hdmi_reset_link(encoder, &ctx); else ret = intel_dp_retrain_link(encoder, &ctx); - - if (ret == -EDEADLK) { - drm_modeset_backoff(&ctx); - continue; - } - - break; } - drm_modeset_drop_locks(&ctx); - drm_modeset_acquire_fini(&ctx); - drm_WARN(encoder->base.dev, ret, - "Acquiring modeset locks failed with %i\n", ret); + drm_WARN_ON(encoder->base.dev, ret); /* * Unpowered type-c dongles can take some time to boot and be diff --git a/drivers/gpu/drm/i915/display/intel_modeset_lock.c b/drivers/gpu/drm/i915/display/intel_modeset_lock.c new file mode 100644 index 0000000000000..8fb6fd849a75d --- /dev/null +++ b/drivers/gpu/drm/i915/display/intel_modeset_lock.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright © 2023 Intel Corporation + */ + +#include <drm/drm_modeset_lock.h> + +#include "intel_display_types.h" +#include "intel_modeset_lock.h" + +void _intel_modeset_lock_begin(struct drm_modeset_acquire_ctx *ctx, + struct intel_atomic_state *state, + unsigned int flags, int *ret) +{ + drm_modeset_acquire_init(ctx, flags); + + if (state) + state->base.acquire_ctx = ctx; + + *ret = -EDEADLK; +} + +bool _intel_modeset_lock_loop(int *ret) +{ + if (*ret == -EDEADLK) { + *ret = 0; + return true; + } + + return false; +} + +void _intel_modeset_lock_end(struct drm_modeset_acquire_ctx *ctx, + struct intel_atomic_state *state, + int *ret) +{ + if (*ret == -EDEADLK) { + if (state) + drm_atomic_state_clear(&state->base); + + *ret = drm_modeset_backoff(ctx); + if (*ret == 0) { + *ret = -EDEADLK; + return; + } + } + + drm_modeset_drop_locks(ctx); + drm_modeset_acquire_fini(ctx); +} diff --git a/drivers/gpu/drm/i915/display/intel_modeset_lock.h b/drivers/gpu/drm/i915/display/intel_modeset_lock.h new file mode 100644 index 0000000000000..edb5099bcd99c --- /dev/null +++ b/drivers/gpu/drm/i915/display/intel_modeset_lock.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: MIT */ +/* + * Copyright © 2023 Intel Corporation + */ + +#ifndef __INTEL_MODESET_LOCK_H__ +#define __INTEL_MODESET_LOCK_H__ + +#include <linux/types.h> + +struct drm_modeset_acquire_ctx; +struct intel_atomic_state; + +void _intel_modeset_lock_begin(struct drm_modeset_acquire_ctx *ctx, + struct intel_atomic_state *state, + unsigned int flags, + int *ret); +bool _intel_modeset_lock_loop(int *ret); +void _intel_modeset_lock_end(struct drm_modeset_acquire_ctx *ctx, + struct intel_atomic_state *state, + int *ret); + +/* + * Note that one must always use "continue" rather than + * "break" or "return" to handle errors within the + * intel_modeset_lock_ctx_retry() block. + */ +#define intel_modeset_lock_ctx_retry(ctx, state, flags, ret) \ + for (_intel_modeset_lock_begin((ctx), (state), (flags), &(ret)); \ + _intel_modeset_lock_loop(&(ret)); \ + _intel_modeset_lock_end((ctx), (state), &(ret))) + +#endif /* __INTEL_MODESET_LOCK_H__ */ -- 2.37.2
