mutex's lead to sleeps which should be avoided in
atomic context.
Hence this patch replaces it with the spin_locks.
Below is the stack trace:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:**
in_atomic(): 1, irqs_disabled(): 1, pid: 89, name: kworker/u4:3
CPU: 1 PID: 89 Comm: kworker/u4:3 Tainted: G W 4.14.43 #8
Workqueue: events_unbound commit_work
Call Trace:
dump_stack+0x4d/0x63
___might_sleep+0x11f/0x12e
mutex_lock+0x20/0x42
amdgpu_atom_execute_table+0x26/0x72
enable_disp_power_gating_v2_1+0x85/0xae
dce110_enable_display_power_gating+0x83/0x1b1
dce110_power_down_fe+0x4a/0x6d
dc_post_update_surfaces_to_stream+0x59/0x87
amdgpu_dm_do_flip+0x239/0x298
amdgpu_dm_commit_planes.isra.23+0x379/0x54b
? drm_calc_timestamping_constants+0x14b/0x15c
amdgpu_dm_atomic_commit_tail+0x4fc/0x5d2
? wait_for_common+0x5b/0x69
commit_tail+0x42/0x64
process_one_work+0x1b0/0x314
worker_thread+0x1cb/0x2c1
? create_worker+0x1da/0x1da
kthread+0x156/0x15e
? kthread_flush_work+0xea/0xea
ret_from_fork+0x22/0x40
V2: Added stack trace in commit message.
Signed-off-by: Shirish S <shirish.s at amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c | 2 +-
drivers/gpu/drm/amd/amdgpu/atom.c | 4 ++--
drivers/gpu/drm/amd/amdgpu/atom.h | 3 ++-
3 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
index bf872f6..ba3d4b9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
@@ -2033,7 +2033,7 @@ int amdgpu_atombios_init(struct amdgpu_device *adev)
return -ENOMEM;
}
- mutex_init(&adev->mode_info.atom_context->mutex);
+ spin_lock_init(&adev->mode_info.atom_context->lock);
if (adev->is_atom_fw) {
amdgpu_atomfirmware_scratch_regs_init(adev);
amdgpu_atomfirmware_allocate_fb_scratch(adev);
diff --git a/drivers/gpu/drm/amd/amdgpu/atom.c b/drivers/gpu/drm/amd/amdgpu/atom.c
index 69500a8..bfd98f0 100644
--- a/drivers/gpu/drm/amd/amdgpu/atom.c
+++ b/drivers/gpu/drm/amd/amdgpu/atom.c
@@ -1261,7 +1261,7 @@ int amdgpu_atom_execute_table(struct atom_context *ctx, int index, uint32_t * pa
{
int r;
- mutex_lock(&ctx->mutex);
+ spin_lock(&ctx->lock);
/* reset data block */
ctx->data_block = 0;
/* reset reg block */
@@ -1274,7 +1274,7 @@ int amdgpu_atom_execute_table(struct atom_context *ctx, int index, uint32_t * pa
ctx->divmul[0] = 0;
ctx->divmul[1] = 0;
r = amdgpu_atom_execute_table_locked(ctx, index, params);
- mutex_unlock(&ctx->mutex);
+ spin_unlock(&ctx->lock);
return r;
}
diff --git a/drivers/gpu/drm/amd/amdgpu/atom.h b/drivers/gpu/drm/amd/amdgpu/atom.h
index a391709..54063e2 100644
--- a/drivers/gpu/drm/amd/amdgpu/atom.h
+++ b/drivers/gpu/drm/amd/amdgpu/atom.h
@@ -26,6 +26,7 @@
#define ATOM_H
#include <linux/types.h>
+#include <linux/spinlock_types.h>
#include <drm/drmP.h>
#define ATOM_BIOS_MAGIC 0xAA55
@@ -125,7 +126,7 @@ struct card_info {
struct atom_context {
struct card_info *card;
- struct mutex mutex;
+ spinlock_t lock;
void *bios;
uint32_t cmd_table, data_table;
uint16_t *iio;
--
2.7.4
