drm/dp: add a hw mutex around the transfer functions. (v2)

[cascardo/linux.git] / drivers / gpu / drm / radeon / radeon_i2c.c

diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c
index 7b94414..add6220 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_i2c.c
+++ b/drivers/gpu/drm/radeon/radeon_i2c.c
@@ -94,6 +94,8 @@ static int pre_xfer(struct i2c_adapter *i2c_adap)
        struct radeon_i2c_bus_rec *rec = &i2c->rec;
        uint32_t temp;
 
+       mutex_lock(&i2c->mutex);
+
        /* RV410 appears to have a bug where the hw i2c in reset
         * holds the i2c port in a bad state - switch hw i2c away before
         * doing DDC - do this for all r200s/r300s/r400s for safety sake
@@ -170,6 +172,8 @@ static void post_xfer(struct i2c_adapter *i2c_adap)
        temp = RREG32(rec->mask_data_reg) & ~rec->mask_data_mask;
        WREG32(rec->mask_data_reg, temp);
        temp = RREG32(rec->mask_data_reg);
+
+       mutex_unlock(&i2c->mutex);
 }
 
 static int get_clock(void *i2c_priv)
@@ -813,6 +817,8 @@ static int radeon_hw_i2c_xfer(struct i2c_adapter *i2c_adap,
        struct radeon_i2c_bus_rec *rec = &i2c->rec;
        int ret = 0;
 
+       mutex_lock(&i2c->mutex);
+
        switch (rdev->family) {
        case CHIP_R100:
        case CHIP_RV100:
@@ -879,6 +885,8 @@ static int radeon_hw_i2c_xfer(struct i2c_adapter *i2c_adap,
                break;
        }
 
+       mutex_unlock(&i2c->mutex);
+
        return ret;
 }
 
@@ -919,6 +927,7 @@ struct radeon_i2c_chan *radeon_i2c_create(struct drm_device *dev,
        i2c->adapter.dev.parent = &dev->pdev->dev;
        i2c->dev = dev;
        i2c_set_adapdata(&i2c->adapter, i2c);
+       mutex_init(&i2c->mutex);
        if (rec->mm_i2c ||
            (rec->hw_capable &&
             radeon_hw_i2c &&
@@ -979,7 +988,7 @@ void radeon_i2c_destroy(struct radeon_i2c_chan *i2c)
                return;
        i2c_del_adapter(&i2c->adapter);
        if (i2c->has_aux)
-               drm_dp_aux_unregister_i2c_bus(&i2c->aux);
+               drm_dp_aux_unregister(&i2c->aux);
        kfree(i2c);
 }