Revert "media: uvcvideo: Require entities to have a non-zero unique ID"

This reverts commit 3dd075fe8ebbc6fcbf998f81a75b8c4b159a6195.

Tomasz has reported that his device, Generalplus Technology Inc. 808 Camera,
with ID 1b3f:2002, stopped being detected:

$ ls -l /dev/video*
zsh: no matches found: /dev/video*
[    7.230599] usb 3-2: Found multiple Units with ID 5

This particular device is non-compliant, having both the Output Terminal
and Processing Unit with ID 5. uvc_scan_fallback, though, is able to build
a chain. However, when media elements are added and uvc_mc_create_links
call uvc_entity_by_id, it will get the incorrect entity,
media_create_pad_link will WARN, and it will fail to register the entities.

In order to reinstate support for such devices in a timely fashion,
reverting the fix for these warnings is appropriate. A proper fix that
considers the existence of such non-compliant devices will be submitted in
a later development cycle.

Reported-by: Tomasz Sikora <sikora.tomus@gmail.com>
Fixes: 3dd075fe8ebb ("media: uvcvideo: Require entities to have a non-zero unique ID")
Cc: stable@vger.kernel.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
Link: https://lore.kernel.org/r/20250114200045.1401644-1-cascardo@igalia.com
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index a10d4f4d9f95f97d586ffc037c9fcc796e97738a..deadbcea5e227c832976fd176c7cdbfd7809c608 100644 (file)
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -790,27 +790,14 @@ static const u8 uvc_media_transport_input_guid[16] =
        UVC_GUID_UVC_MEDIA_TRANSPORT_INPUT;
 static const u8 uvc_processing_guid[16] = UVC_GUID_UVC_PROCESSING;
 
-static struct uvc_entity *uvc_alloc_new_entity(struct uvc_device *dev, u16 type,
-                                              u16 id, unsigned int num_pads,
-                                              unsigned int extra_size)
+static struct uvc_entity *uvc_alloc_entity(u16 type, u16 id,
+               unsigned int num_pads, unsigned int extra_size)
 {
        struct uvc_entity *entity;
        unsigned int num_inputs;
        unsigned int size;
        unsigned int i;
 
-       /* Per UVC 1.1+ spec 3.7.2, the ID should be non-zero. */
-       if (id == 0) {
-               dev_err(&dev->udev->dev, "Found Unit with invalid ID 0.\n");
-               return ERR_PTR(-EINVAL);
-       }
-
-       /* Per UVC 1.1+ spec 3.7.2, the ID is unique. */
-       if (uvc_entity_by_id(dev, id)) {
-               dev_err(&dev->udev->dev, "Found multiple Units with ID %u\n", id);
-               return ERR_PTR(-EINVAL);
-       }
-
        extra_size = roundup(extra_size, sizeof(*entity->pads));
        if (num_pads)
                num_inputs = type & UVC_TERM_OUTPUT ? num_pads : num_pads - 1;
@@ -820,7 +807,7 @@ static struct uvc_entity *uvc_alloc_new_entity(struct uvc_device *dev, u16 type,
             + num_inputs;
        entity = kzalloc(size, GFP_KERNEL);
        if (entity == NULL)
-               return ERR_PTR(-ENOMEM);
+               return NULL;
 
        entity->id = id;
        entity->type = type;
@@ -932,10 +919,10 @@ static int uvc_parse_vendor_control(struct uvc_device *dev,
                        break;
                }
 
-               unit = uvc_alloc_new_entity(dev, UVC_VC_EXTENSION_UNIT,
-                                           buffer[3], p + 1, 2 * n);
-               if (IS_ERR(unit))
-                       return PTR_ERR(unit);
+               unit = uvc_alloc_entity(UVC_VC_EXTENSION_UNIT, buffer[3],
+                                       p + 1, 2*n);
+               if (unit == NULL)
+                       return -ENOMEM;
 
                memcpy(unit->guid, &buffer[4], 16);
                unit->extension.bNumControls = buffer[20];
@@ -1044,10 +1031,10 @@ static int uvc_parse_standard_control(struct uvc_device *dev,
                        return -EINVAL;
                }
 
-               term = uvc_alloc_new_entity(dev, type | UVC_TERM_INPUT,
-                                           buffer[3], 1, n + p);
-               if (IS_ERR(term))
-                       return PTR_ERR(term);
+               term = uvc_alloc_entity(type | UVC_TERM_INPUT, buffer[3],
+                                       1, n + p);
+               if (term == NULL)
+                       return -ENOMEM;
 
                if (UVC_ENTITY_TYPE(term) == UVC_ITT_CAMERA) {
                        term->camera.bControlSize = n;
@@ -1103,10 +1090,10 @@ static int uvc_parse_standard_control(struct uvc_device *dev,
                        return 0;
                }
 
-               term = uvc_alloc_new_entity(dev, type | UVC_TERM_OUTPUT,
-                                           buffer[3], 1, 0);
-               if (IS_ERR(term))
-                       return PTR_ERR(term);
+               term = uvc_alloc_entity(type | UVC_TERM_OUTPUT, buffer[3],
+                                       1, 0);
+               if (term == NULL)
+                       return -ENOMEM;
 
                memcpy(term->baSourceID, &buffer[7], 1);
 
@@ -1125,10 +1112,9 @@ static int uvc_parse_standard_control(struct uvc_device *dev,
                        return -EINVAL;
                }
 
-               unit = uvc_alloc_new_entity(dev, buffer[2], buffer[3],
-                                           p + 1, 0);
-               if (IS_ERR(unit))
-                       return PTR_ERR(unit);
+               unit = uvc_alloc_entity(buffer[2], buffer[3], p + 1, 0);
+               if (unit == NULL)
+                       return -ENOMEM;
 
                memcpy(unit->baSourceID, &buffer[5], p);
 
@@ -1148,9 +1134,9 @@ static int uvc_parse_standard_control(struct uvc_device *dev,
                        return -EINVAL;
                }
 
-               unit = uvc_alloc_new_entity(dev, buffer[2], buffer[3], 2, n);
-               if (IS_ERR(unit))
-                       return PTR_ERR(unit);
+               unit = uvc_alloc_entity(buffer[2], buffer[3], 2, n);
+               if (unit == NULL)
+                       return -ENOMEM;
 
                memcpy(unit->baSourceID, &buffer[4], 1);
                unit->processing.wMaxMultiplier =
@@ -1177,10 +1163,9 @@ static int uvc_parse_standard_control(struct uvc_device *dev,
                        return -EINVAL;
                }
 
-               unit = uvc_alloc_new_entity(dev, buffer[2], buffer[3],
-                                           p + 1, n);
-               if (IS_ERR(unit))
-                       return PTR_ERR(unit);
+               unit = uvc_alloc_entity(buffer[2], buffer[3], p + 1, n);
+               if (unit == NULL)
+                       return -ENOMEM;
 
                memcpy(unit->guid, &buffer[4], 16);
                unit->extension.bNumControls = buffer[20];
@@ -1320,10 +1305,9 @@ static int uvc_gpio_parse(struct uvc_device *dev)
                return dev_err_probe(&dev->intf->dev, irq,
                                     "No IRQ for privacy GPIO\n");
 
-       unit = uvc_alloc_new_entity(dev, UVC_EXT_GPIO_UNIT,
-                                   UVC_EXT_GPIO_UNIT_ID, 0, 1);
-       if (IS_ERR(unit))
-               return PTR_ERR(unit);
+       unit = uvc_alloc_entity(UVC_EXT_GPIO_UNIT, UVC_EXT_GPIO_UNIT_ID, 0, 1);
+       if (!unit)
+               return -ENOMEM;
 
        unit->gpio.gpio_privacy = gpio_privacy;
        unit->gpio.irq = irq;