drm/radeon: finish getting bios earlier

Return a number of bytes read in radeon_atrm_get_bios_chunk() and
properly check this value in radeon_atrm_get_bios().
If radeon_atrm_get_bios_chunk() read less bytes then were requested,
it means that it finished reading bios data.

Prior to this patch, condition in radeon_atrm_get_bios() was always
equivalent to "if (ATRM_BIOS_PAGE <= 0)", so it was always false,
thus radeon_atrm_get_bios() was trying to read past the bios data
wasting boot time.

On my lenovo ideapad u455 laptop this patch drops bios reading time
from ~5.5s to ~1.5s.

Signed-off-by: Igor Murzov <e-mail@date.by>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 2 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_atpx_handler.c b/drivers/gpu/drm/radeon/radeon_atpx_handler.c
index c666a5b5e505..13ac63ba6075 100644
--- a/drivers/gpu/drm/radeon/radeon_atpx_handler.c
+++ b/drivers/gpu/drm/radeon/radeon_atpx_handler.c
@@ -60,7 +60,7 @@ static int radeon_atrm_call(acpi_handle atrm_handle, uint8_t *bios,
         obj = (union acpi_object *)buffer.pointer;
         memcpy(bios+offset, obj->buffer.pointer, obj->buffer.length);
         kfree(buffer.pointer);
-        return len;
+        return obj->buffer.length;
 }
 
 bool radeon_atrm_supported(struct pci_dev *pdev)
diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c
index 229a20f10e2b..501f4881e5aa 100644
--- a/drivers/gpu/drm/radeon/radeon_bios.c
+++ b/drivers/gpu/drm/radeon/radeon_bios.c
@@ -120,7 +120,7 @@ static bool radeon_atrm_get_bios(struct radeon_device *rdev)
                 ret = radeon_atrm_get_bios_chunk(rdev->bios,
                                                  (i * ATRM_BIOS_PAGE),
                                                  ATRM_BIOS_PAGE);
-                if (ret <= 0)
+                if (ret < ATRM_BIOS_PAGE)
                         break;
         }