amdgpu: Abort probing if firmware is not installed, as we do in radeon

debian/changelog

@@ -402,6 +402,7 @@ linux (4.15.9-1) UNRELEASED; urgency=medium
     __flush_tlb_one_[user|kernel]()" to avoid an ABI change
   * [x86] Revert "x86/debug: Use UD2 for WARN()" to avoid an ABI change
   * drm/atomic: Avoid ABI change in 4.15.7
+  * amdgpu: Abort probing if firmware is not installed, as we do in radeon
 
   [ Uwe Kleine-König ]
   * netfilter: enable NFT_FIB_NETDEV as module

debian/patches/bugfix/all/radeon-amdgpu-firmware-is-required-for-drm-and-kms-on-r600-onward.patch

@@ -1,5 +1,5 @@
 From: Ben Hutchings <ben@decadent.org.uk>
-Subject: radeon: Firmware is required for DRM and KMS on R600 onward
+Subject: radeon, amdgpu: Firmware is required for DRM and KMS on R600 onward
 Date: Tue, 08 Jan 2013 03:25:52 +0000
 Bug-Debian: https://bugs.debian.org/607194
 Bug-Debian: https://bugs.debian.org/607471
@@ -20,8 +20,8 @@ the firmware is not available, but becomes unstable - the framebuffer
 and/or system memory may be corrupted, or the display may stay black.
 
 Therefore, perform a basic check for the existence of
-/lib/firmware/radeon when a device is probed, and abort if it is
+/lib/firmware/{radeon,amdgpu} when a device is probed, and abort if it
-missing, except for the pre-R600 case.
+is missing, except for the pre-R600 case.
 
 ---
 --- a/drivers/gpu/drm/radeon/radeon_drv.c
@@ -77,3 +77,55 @@ missing, except for the pre-R600 case.
  	/* Get rid of things like offb */
  	ret = radeon_kick_out_firmware_fb(pdev);
  	if (ret)
+--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
++++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+@@ -40,6 +40,8 @@
+ #include <linux/pm_runtime.h>
+ #include <linux/vga_switcheroo.h>
+ #include <drm/drm_crtc_helper.h>
++#include <linux/namei.h>
++#include <linux/path.h>
+ 
+ #include "amdgpu.h"
+ #include "amdgpu_irq.h"
+@@ -545,6 +547,28 @@ MODULE_DEVICE_TABLE(pci, pciidlist);
+ 
+ static struct drm_driver kms_driver;
+ 
++/* Test that /lib/firmware/amdgpu is a directory (or symlink to a
++ * directory).  We could try to match the udev search path, but let's
++ * keep it simple.
++ */
++static bool amdgpu_firmware_installed(void)
++{
++#if IS_BUILTIN(CONFIG_DRM_AMDGPU)
++	/* It may be too early to tell.  Assume it's there. */
++	return true;
++#else
++	struct path path;
++
++	if (kern_path("/lib/firmware/amdgpu", LOOKUP_DIRECTORY | LOOKUP_FOLLOW,
++		      &path) == 0) {
++		path_put(&path);
++		return true;
++	}
++
++	return false;
++#endif
++}
++
+ static int amdgpu_kick_out_firmware_fb(struct pci_dev *pdev)
+ {
+ 	struct apertures_struct *ap;
+@@ -579,6 +603,11 @@ static int amdgpu_pci_probe(struct pci_d
+ 		return -ENODEV;
+ 	}
+ 
++	if (!amdgpu_firmware_installed()) {
++		DRM_ERROR("amdgpu requires firmware installed\n");
++		return -ENODEV;
++	}
++
+ 	/*
+ 	 * Initialize amdkfd before starting radeon. If it was not loaded yet,
+ 	 * defer radeon probing

debian/patches/debian/firmware_class-refer-to-debian-wiki-firmware-page.patch

@@ -9,6 +9,10 @@ message referring to our wiki page about firmware.  This will explain
 why some firmware is in non-free, or can't be packaged at all.  Only
 do this once per boot.
 
+Do something similar in the radeon and amdgpu drivers, where we have
+an early check to avoid failing at a point where we cannot display
+anything.
+
 ---
 --- a/drivers/base/firmware_class.c
 +++ b/drivers/base/firmware_class.c
@@ -36,3 +40,13 @@ do this once per boot.
  		return -ENODEV;
  	}
  
+--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
++++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+@@ -605,6 +605,7 @@ static int amdgpu_pci_probe(struct pci_d
+ 
+ 	if (!amdgpu_firmware_installed()) {
+ 		DRM_ERROR("amdgpu requires firmware installed\n");
++		pr_err_once("See https://wiki.debian.org/Firmware for information about missing firmware\n");
+ 		return -ENODEV;
+ 	}
+ 

debian/patches/series

@@ -16,7 +16,7 @@ features/all/drivers-media-dvb-usb-af9005-request_firmware.patch
 debian/iwlwifi-do-not-request-unreleased-firmware.patch
 bugfix/all/firmware_class-log-every-success-and-failure.patch
 bugfix/all/firmware-remove-redundant-log-messages-from-drivers.patch
-bugfix/all/radeon-firmware-is-required-for-drm-and-kms-on-r600-onward.patch
+bugfix/all/radeon-amdgpu-firmware-is-required-for-drm-and-kms-on-r600-onward.patch
 debian/firmware_class-refer-to-debian-wiki-firmware-page.patch
 
 # Patches from aufs4 repository, imported with