[PATCH 07/12] drm/udl: Add parameter to set number of URBs

[Takashi Iwai <tiwai@xxxxxxx>]

From: Thomas Zimmermann <tzimmermann@xxxxxxx>

For further debugging and optimization purpose, allow users to adjust
the number of URBs via a new module parameter, numurbs.

Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
 drivers/gpu/drm/udl/udl_main.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
index 2b7eafd48ec2..3c97f647883f 100644
--- a/drivers/gpu/drm/udl/udl_main.c
+++ b/drivers/gpu/drm/udl/udl_main.c
@@ -8,6 +8,8 @@
  * Copyright (C) 2009 Bernie Thompson <bernie@xxxxxxxxxxxx>
  */
 
+#include <linux/moduleparam.h>
+
 #include <drm/drm.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
@@ -23,6 +25,9 @@
 #define WRITES_IN_FLIGHT (20)
 #define MAX_VENDOR_DESCRIPTOR_SIZE 256
 
+static uint udl_num_urbs = WRITES_IN_FLIGHT;
+module_param_named(numurbs, udl_num_urbs, uint, 0600);
+
 static int udl_parse_vendor_descriptor(struct udl_device *udl)
 {
 	struct usb_device *udev = udl_to_usb_device(udl);
@@ -294,6 +299,8 @@ int udl_init(struct udl_device *udl)
 	struct drm_device *dev = &udl->drm;
 	int ret = -ENOMEM;
 
+	drm_info(dev, "pre-allocating %d URBs\n", udl_num_urbs);
+
 	DRM_DEBUG("\n");
 
 	udl->dmadev = usb_intf_get_dma_device(to_usb_interface(dev->dev));
@@ -311,7 +318,7 @@ int udl_init(struct udl_device *udl)
 	if (udl_select_std_channel(udl))
 		DRM_ERROR("Selecting channel failed\n");
 
-	if (!udl_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
+	if (!udl_alloc_urb_list(dev, udl_num_urbs, MAX_TRANSFER)) {
 		DRM_ERROR("udl_alloc_urb_list failed\n");
 		goto err;
 	}
-- 
2.35.3