Merge branch 'drm-fixes-3.18' of git://people.freedesktop.org/~agd5f/linux into drm-fixes

atom scratch register race fix.

* 'drm-fixes-3.18' of git://people.freedesktop.org/~agd5f/linux:
  drm/radeon: add locking around atombios scratch space usage

5 files changed, 19 insertions, 3 deletions

diff --git a/drivers/gpu/drm/radeon/atom.c b/drivers/gpu/drm/radeon/atom.c
index 15da7ef344a4..ec1593a6a561 100644
--- a/drivers/gpu/drm/radeon/atom.c
+++ b/drivers/gpu/drm/radeon/atom.c
@@ -1217,7 +1217,7 @@ 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;
 
@@ -1238,6 +1238,15 @@ 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 feba6b8d36b3..6d014ddb6b78 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;
@@ -145,6 +146,7 @@ extern int atom_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 95d5d4ab3335..11ba9d21b89b 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 9c570fb15b8c..4157780585a0 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 ea2676954dde..995a8b1770dd 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -952,6 +952,7 @@ 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;