drm/udl: Increase GET_URB_TIMEOUT

[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 timeout of getting urb.
2. Add error messages when calling udl_get_urb() failed in
udl_crtc_helper_atomic_enable().

Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 5320918b9a87 ("drm/udl: initial UDL driver (v4)")
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: <stable@vger.kernel.org> # v3.4+
Link: https://patch.msgid.link/20260424124427.657-1-oushixiong1025@163.com

diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
index 08a0e9480d706cafca7e247d2da3a9deb311261a..17950fe3a0ec6482ad82e07a3c1ff70c37199f4e 100644 (file)
--- a/drivers/gpu/drm/udl/udl_main.c
+++ b/drivers/gpu/drm/udl/udl_main.c
@@ -285,13 +285,12 @@ static struct urb *udl_get_urb_locked(struct udl_device *udl, long timeout)
        return unode->urb;
 }
 
-#define GET_URB_TIMEOUT        HZ
 struct urb *udl_get_urb(struct udl_device *udl)
 {
        struct urb *urb;
 
        spin_lock_irq(&udl->urbs.lock);
-       urb = udl_get_urb_locked(udl, GET_URB_TIMEOUT);
+       urb = udl_get_urb_locked(udl, HZ * 2);
        spin_unlock_irq(&udl->urbs.lock);
        return urb;
 }

diff --git a/drivers/gpu/drm/udl/udl_modeset.c b/drivers/gpu/drm/udl/udl_modeset.c
index 231e829bd709a205e7fcc9839fcc790509a8abe9..1ca073a4ecb2504f67d1e29e4f5c33506d413ad6 100644 (file)
--- 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_err_ratelimited(dev, "get urb failed when enabling crtc\n");
                goto out;
+       }
 
        buf = (char *)urb->transfer_buffer;
        buf = udl_vidreg_lock(buf);