drm/radeon/kms: auto detect pcie link speed from root port

This check the root ports supported link speeds and enables
GEN2 mode if the 5.0 GT link speed is available.

The first 3.0 cards are SI so they will probably need more investigation.

Signed-off-by: Dave Airlie <airlied@redhat.com>

4 files changed, 35 insertions, 3 deletions

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 14098ace1569..e585a3b947eb 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -3421,7 +3421,8 @@ void evergreen_fini(struct radeon_device *rdev)
 
 void evergreen_pcie_gen2_enable(struct radeon_device *rdev)
 {
-        u32 link_width_cntl, speed_cntl;
+        u32 link_width_cntl, speed_cntl, mask;
+        int ret;
 
         if (radeon_pcie_gen2 == 0)
                 return;
@@ -3436,6 +3437,15 @@ void evergreen_pcie_gen2_enable(struct radeon_device *rdev)
         if (ASIC_IS_X2(rdev))
                 return;
 
+        ret = drm_pcie_get_speed_cap_mask(rdev->ddev, &mask);
+        if (ret != 0)
+                return;
+
+        if (!(mask & DRM_PCIE_SPEED_50))
+                return;
+
+        DRM_INFO("enabling PCIE gen 2 link speeds, disable with radeon.pcie_gen2=0\n");
+
         speed_cntl = RREG32_PCIE_P(PCIE_LC_SPEED_CNTL);
         if ((speed_cntl & LC_OTHER_SIDE_EVER_SENT_GEN2) ||
             (speed_cntl & LC_OTHER_SIDE_SUPPORTS_GEN2)) {
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index e2dee80e27dc..637280f541a3 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -3681,6 +3681,8 @@ static void r600_pcie_gen2_enable(struct radeon_device *rdev)
 {
         u32 link_width_cntl, lanes, speed_cntl, training_cntl, tmp;
         u16 link_cntl2;
+        u32 mask;
+        int ret;
 
         if (radeon_pcie_gen2 == 0)
                 return;
@@ -3699,6 +3701,15 @@ static void r600_pcie_gen2_enable(struct radeon_device *rdev)
         if (rdev->family <= CHIP_R600)
                 return;
 
+        ret = drm_pcie_get_speed_cap_mask(rdev->ddev, &mask);
+        if (ret != 0)
+                return;
+
+        if (!(mask & DRM_PCIE_SPEED_50))
+                return;
+
+        DRM_INFO("enabling PCIE gen 2 link speeds, disable with radeon.pcie_gen2=0\n");
+
         /* 55 nm r6xx asics */
         if ((rdev->family == CHIP_RV670) ||
             (rdev->family == CHIP_RV620) ||
diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
index 2c4d53fd20c5..042fcfff3bc4 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@@ -133,7 +133,7 @@ int radeon_tv = 1;
 int radeon_audio = 0;
 int radeon_disp_priority = 0;
 int radeon_hw_i2c = 0;
-int radeon_pcie_gen2 = 0;
+int radeon_pcie_gen2 = -1;
 int radeon_msi = -1;
 int radeon_lockup_timeout = 10000;
 
@@ -179,7 +179,7 @@ module_param_named(disp_priority, radeon_disp_priority, int, 0444);
 MODULE_PARM_DESC(hw_i2c, "hw i2c engine enable (0 = disable)");
 module_param_named(hw_i2c, radeon_hw_i2c, int, 0444);
 
-MODULE_PARM_DESC(pcie_gen2, "PCIE Gen2 mode (1 = enable)");
+MODULE_PARM_DESC(pcie_gen2, "PCIE Gen2 mode (-1 = auto, 0 = disable, 1 = enable)");
 module_param_named(pcie_gen2, radeon_pcie_gen2, int, 0444);
 
 MODULE_PARM_DESC(msi, "MSI support (1 = enable, 0 = disable, -1 = auto)");
diff --git a/drivers/gpu/drm/radeon/rv770.c b/drivers/gpu/drm/radeon/rv770.c
index eb4704e72bdb..ca8ffec10ff6 100644
--- a/drivers/gpu/drm/radeon/rv770.c
+++ b/drivers/gpu/drm/radeon/rv770.c
@@ -1112,6 +1112,8 @@ static void rv770_pcie_gen2_enable(struct radeon_device *rdev)
 {
         u32 link_width_cntl, lanes, speed_cntl, tmp;
         u16 link_cntl2;
+        u32 mask;
+        int ret;
 
         if (radeon_pcie_gen2 == 0)
                 return;
@@ -1126,6 +1128,15 @@ static void rv770_pcie_gen2_enable(struct radeon_device *rdev)
         if (ASIC_IS_X2(rdev))
                 return;
 
+        ret = drm_pcie_get_speed_cap_mask(rdev->ddev, &mask);
+        if (ret != 0)
+                return;
+
+        if (!(mask & DRM_PCIE_SPEED_50))
+                return;
+
+        DRM_INFO("enabling PCIE gen 2 link speeds, disable with radeon.pcie_gen2=0\n");
+
         /* advertise upconfig capability */
         link_width_cntl = RREG32_PCIE_P(PCIE_LC_LINK_WIDTH_CNTL);
         link_width_cntl &= ~LC_UPCONFIGURE_DIS;