From: Dave Airlie <airl...@redhat.com>
While developing MST support I noticed I often got the wrong data
back from a transaction, in a racy fashion. I noticed the scratch
space wasn't locked against concurrent users.
Based on a patch by Alex, but I've made it a bit more obvious when
things are locked.
Signed-off-by: Dave Airlie <airlied at redhat.com>
---
drivers/gpu/drm/radeon/atom.c | 11 ++++++++++-
drivers/gpu/drm/radeon/atom.h | 2 ++
drivers/gpu/drm/radeon/atombios_dp.c | 4 +++-
drivers/gpu/drm/radeon/atombios_i2c.c | 4 +++-
drivers/gpu/drm/radeon/radeon_device.c | 1 +
5 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/radeon/atom.c b/drivers/gpu/drm/radeon/atom.c
index 6f26eb7..bec41c4 100644
--- a/drivers/gpu/drm/radeon/atom.c
+++ b/drivers/gpu/drm/radeon/atom.c
@@ -1218,7 +1218,7 @@ free:
return ret;
}
-int atom_execute_table(struct atom_context *ctx, int index, uint32_t * params)
+int atom_execute_table_scratch_unlocked(struct atom_context *ctx, int index,
uint32_t * params)
{
int r;
@@ -1239,6 +1239,15 @@ int atom_execute_table(struct atom_context *ctx, int
index, uint32_t * params)
return r;
}
+int atom_execute_table(struct atom_context *ctx, int index, uint32_t * params)
+{
+ int r;
+ mutex_lock(&ctx->scratch_mutex);
+ r = atom_execute_table_scratch_unlocked(ctx, index, params);
+ mutex_unlock(&ctx->scratch_mutex);
+ return r;
+}
+
static int atom_iio_len[] = { 1, 2, 3, 3, 3, 3, 4, 4, 4, 3 };
static void atom_index_iio(struct atom_context *ctx, int base)
diff --git a/drivers/gpu/drm/radeon/atom.h b/drivers/gpu/drm/radeon/atom.h
index bf9e6f2..6dffe15 100644
--- a/drivers/gpu/drm/radeon/atom.h
+++ b/drivers/gpu/drm/radeon/atom.h
@@ -125,6 +125,7 @@ struct card_info {
struct atom_context {
struct card_info *card;
struct mutex mutex;
+ struct mutex scratch_mutex;
void *bios;
uint32_t cmd_table, data_table;
uint16_t *iio;
@@ -146,6 +147,7 @@ extern int atom_reg_debug;
struct atom_context *atom_parse(struct card_info *, void *);
int atom_execute_table(struct atom_context *, int, uint32_t *);
+int atom_execute_table_scratch_unlocked(struct atom_context *, int, uint32_t
*);
int atom_asic_init(struct atom_context *);
void atom_destroy(struct atom_context *);
bool atom_parse_data_header(struct atom_context *ctx, int index, uint16_t
*size,
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c
b/drivers/gpu/drm/radeon/atombios_dp.c
index bd96ae7..0f39d96 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -100,6 +100,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan
*chan,
memset(&args, 0, sizeof(args));
mutex_lock(&chan->mutex);
+ mutex_lock(&rdev->mode_info.atom_context->scratch_mutex);
base = (unsigned char *)(rdev->mode_info.atom_context->scratch + 1);
@@ -113,7 +114,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan
*chan,
if (ASIC_IS_DCE4(rdev))
args.v2.ucHPD_ID = chan->rec.hpd;
- atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t
*)&args);
+ atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context,
index, (uint32_t *)&args);
*ack = args.v1.ucReplyStatus;
@@ -147,6 +148,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan
*chan,
r = recv_bytes;
done:
+ mutex_unlock(&rdev->mode_info.atom_context->scratch_mutex);
mutex_unlock(&chan->mutex);
return r;
diff --git a/drivers/gpu/drm/radeon/atombios_i2c.c
b/drivers/gpu/drm/radeon/atombios_i2c.c
index 9c570fb..4157780 100644
--- a/drivers/gpu/drm/radeon/atombios_i2c.c
+++ b/drivers/gpu/drm/radeon/atombios_i2c.c
@@ -48,6 +48,7 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan,
memset(&args, 0, sizeof(args));
mutex_lock(&chan->mutex);
+ mutex_lock(&rdev->mode_info.atom_context->scratch_mutex);
base = (unsigned char *)rdev->mode_info.atom_context->scratch;
@@ -82,7 +83,7 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan,
args.ucSlaveAddr = slave_addr << 1;
args.ucLineNumber = chan->rec.i2c_id;
- atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t
*)&args);
+ atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context,
index, (uint32_t *)&args);
/* error */
if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
@@ -95,6 +96,7 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan,
radeon_atom_copy_swap(buf, base, num, false);
done:
+ mutex_unlock(&rdev->mode_info.atom_context->scratch_mutex);
mutex_unlock(&chan->mutex);
return r;
diff --git a/drivers/gpu/drm/radeon/radeon_device.c
b/drivers/gpu/drm/radeon/radeon_device.c
index 0d77dce..e63c9a4 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -950,6 +950,7 @@ int radeon_atombios_init(struct radeon_device *rdev)
}
mutex_init(&rdev->mode_info.atom_context->mutex);
+ mutex_init(&rdev->mode_info.atom_context->scratch_mutex);
radeon_atom_initialize_bios_scratch_regs(rdev->ddev);
atom_allocate_fb_scratch(rdev->mode_info.atom_context);
return 0;
--
1.9.3
