Tentative fix for NVIDIA 470.256.02 driver for Linux 6.12-rc1

nvidia-470xx-fix-linux-6.12.patch

From 839b964bd5be20275a4d1add020e68e407380adb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joan=20Bruguera=20Mic=C3=B3?= <[email protected]>
Date: Sat, 17 Aug 2024 14:26:04 +0000
Subject: [PATCH] Tentative fix for NVIDIA 470.256.02 driver for Linux 6.12-rc1

Note that the fix requires enabling DRM kernel mode setting
(add the `nvidia-drm.modeset=1` parameter to the kernel command line).

(Thanks xtexChooser for the memory management fixes!)
---
 nvidia-drm/nvidia-drm-drv.c | 47 +++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/nvidia-drm/nvidia-drm-drv.c b/nvidia-drm/nvidia-drm-drv.c
index f350134..d6233a5 100644
--- a/nvidia-drm/nvidia-drm-drv.c
+++ b/nvidia-drm/nvidia-drm-drv.c
@@ -84,6 +84,11 @@
 #include <drm/drm_atomic_helper.h>
 #endif
 
+#include <linux/version.h>
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 12, 0)
+#include <drm/drm_client.h>
+#endif
+
 static struct nv_drm_device *dev_list = NULL;
 
 #if defined(NV_DRM_ATOMIC_MODESET_AVAILABLE)
@@ -168,7 +173,12 @@ static const struct drm_mode_config_funcs nv_mode_config_funcs = {
     .atomic_check  = nv_drm_atomic_check,
     .atomic_commit = nv_drm_atomic_commit,
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 12, 0)
+    // Rel. commit. "drm: Remove struct drm_mode_config_funcs.output_poll_changed" (Thomas Zimmermann, 12 Aug 2024)
+    // Replace this callback with a DRM client's hotplug callback.
+    // This is required for e.g. /sys/class/drm/card*/modes to work.
     .output_poll_changed = nv_drm_output_poll_changed,
+#endif
 };
 
 static void nv_drm_event_callback(const struct NvKmsKapiEvent *event)
@@ -739,6 +749,10 @@ static const struct file_operations nv_drm_fops = {
     .read           = drm_read,
 
     .llseek         = noop_llseek,
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 12, 0)
+    // Rel. commit. "fs: move FMODE_UNSIGNED_OFFSET to fop_flags" (Christian Brauner, 9 Aug 2024)
+    .fop_flags      = FOP_UNSIGNED_OFFSET,
+#endif
 };
 
 static const struct drm_ioctl_desc nv_drm_ioctls[] = {
@@ -906,7 +920,18 @@ static void nv_drm_update_drm_driver_features(void)
 #endif /* NV_DRM_ATOMIC_MODESET_AVAILABLE */
 }
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 12, 0)
+static int hotplug_helper_client_hotplug(struct drm_client_dev *client)
+{
+    nv_drm_output_poll_changed(client->dev);
+    return 0;
+}
 
+static const struct drm_client_funcs nv_hotplug_helper_client_funcs = {
+    .owner      = THIS_MODULE,
+    .hotplug    = hotplug_helper_client_hotplug,
+};
+#endif
 
 /*
  * Helper function for allocate/register DRM device for given NVIDIA GPU ID.
@@ -962,6 +987,20 @@ static void nv_drm_register_drm_device(const nv_gpu_info_t *gpu_info)
         goto failed_drm_register;
     }
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 12, 0)
+    /* Register a DRM client for receiving hotplug events */
+    struct drm_client_dev *client = kzalloc(sizeof(*client), GFP_KERNEL);
+    if (client == NULL || drm_client_init(dev, client,
+        "nv-hotplug-helper", &nv_hotplug_helper_client_funcs)) {
+        printk(KERN_WARNING "Failed to initialize the nv-hotplug-helper DRM client"
+            " (ensure DRM kernel mode setting is enabled via nvidia-drm.modeset=1).\n");
+        goto failed_drm_client_init;
+    }
+
+    drm_client_register(client);
+    pr_info("Registered the nv-hotplug-helper DRM client.\n");
+#endif
+
     /* Add NVIDIA-DRM device into list */
 
     nv_dev->next = dev_list;
@@ -969,6 +1008,14 @@ static void nv_drm_register_drm_device(const nv_gpu_info_t *gpu_info)
 
     return; /* Success */
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 12, 0)
+failed_drm_client_init:
+
+    kfree(client);
+    drm_dev_unregister(dev);
+
+#endif
+
 failed_drm_register:
 
     nv_drm_dev_free(dev);
-- 
2.47.0

Hello, just to say this patch works perfectly for me in Mint 22 running the Liquorix 6.12 kernel. Thanks so much for keeping my GT710 working!

Hello joanbm.
And I've already completely lost hope. I can't install your patch. The following error appears
pastedbin
My video-device GeForce GT730
My OS Gentoo
Help me please

@ShprotOFF It seems that it fails to apply the patch, not compiling the driver.

Perhaps gentoo has modified the NVIDIA drivers (file is called nvidia-drivers-470.256.02-r2) so that the patch is confused? I can't say.

Perhaps if you try to manually download the NVIDIA driver, apply the patches and then compile the drivers yourself? This is what I have been doing from long time ago.
I use the script mentioned here (perhaps you do not need the last patch):

https://gist.github.com/joanbm/d1f89391a4b20f4b56ba931ef6ca62da?permalink_comment_id=5461139#gistcomment-5461139

Once you patch the driver, you need to compile and install:

cd NVIDIA-Linux-x86_64-470.256.02
./nvidia-installer

@hadjiprocopis @joanbm Oh, my God...!!! It worked! Thank you so much! If you're in Vladivostok, let me know! I'll treat you to crabs with delicious beer.

@ShprotOFF Cool, next time I am in Vladivostok I will give you a call!!! hehe best wishes!