From: Shixiong Ou <[email protected]>

[WHY]
A situation has occurred where udl_handle_damage() executed successfully
and the kernel log appears normal, but the display fails to show any output.
This is because the call to udl_get_urb() in udl_crtc_helper_atomic_enable()
failed without generating any error message.

[HOW]
1. Increase GET_URB_TIMEOUT.
2. Add error messages when calling udl_get_urb() failed in
udl_crtc_helper_atomic_enable().

Signed-off-by: Shixiong Ou <[email protected]>
---
 drivers/gpu/drm/udl/udl_main.c    | 2 +-
 drivers/gpu/drm/udl/udl_modeset.c | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
index bc58991a6f14..dd9576fd4ff0 100644
--- a/drivers/gpu/drm/udl/udl_main.c
+++ b/drivers/gpu/drm/udl/udl_main.c
@@ -285,7 +285,7 @@ static struct urb *udl_get_urb_locked(struct udl_device 
*udl, long timeout)
        return unode->urb;
 }
 
-#define GET_URB_TIMEOUT        HZ
+#define GET_URB_TIMEOUT        (HZ * 2)
 struct urb *udl_get_urb(struct udl_device *udl)
 {
        struct urb *urb;
diff --git a/drivers/gpu/drm/udl/udl_modeset.c 
b/drivers/gpu/drm/udl/udl_modeset.c
index 231e829bd709..647af04f194e 100644
--- a/drivers/gpu/drm/udl/udl_modeset.c
+++ b/drivers/gpu/drm/udl/udl_modeset.c
@@ -21,6 +21,7 @@
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_gem_shmem_helper.h>
 #include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_vblank.h>
 
@@ -342,8 +343,10 @@ static void udl_crtc_helper_atomic_enable(struct drm_crtc 
*crtc, struct drm_atom
                return;
 
        urb = udl_get_urb(udl);
-       if (!urb)
+       if (!urb) {
+               DRM_ERROR("Udl get urb failed when enabling crtc");
                goto out;
+       }
 
        buf = (char *)urb->transfer_buffer;
        buf = udl_vidreg_lock(buf);
-- 
2.25.1

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