radeon, amdgpu: Firmware is required for DRM and KMS on R600 onward

Bug-Debian: https://bugs.debian.org/607194
Bug-Debian: https://bugs.debian.org/607471
Bug-Debian: https://bugs.debian.org/610851
Bug-Debian: https://bugs.debian.org/627497
Bug-Debian: https://bugs.debian.org/632212
Bug-Debian: https://bugs.debian.org/637943
Bug-Debian: https://bugs.debian.org/649448
Bug-Debian: https://bugs.debian.org/697229
Forwarded: no

radeon requires firmware/microcode for the GPU in all chips, but for
newer chips (apparently R600 'Evergreen' onward) it also expects
firmware for the memory controller and other sub-blocks.

radeon attempts to gracefully fall back and disable some features if
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,amdgpu} when a device is probed, and abort if it
is missing, except for the pre-R600 case.

Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name radeon-amdgpu-firmware-is-required-for-drm-and-kms-on-r600-onward.patch

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index f999638a04ed6a003aaf9d2554db2f3777891c1d..5355dc460c31a701c3ec1b373e4c703ff1951e1a 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -40,6 +40,8 @@
 #include <linux/suspend.h>
 #include <linux/cc_platform.h>
 #include <linux/fb.h>
+#include <linux/namei.h>
+#include <linux/path.h>
 
 #include "amdgpu.h"
 #include "amdgpu_irq.h"
@@ -1992,6 +1994,28 @@ static bool amdgpu_is_fw_framebuffer(resource_size_t base,
        return found;
 }
 
+/* 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_pci_probe(struct pci_dev *pdev,
                            const struct pci_device_id *ent)
 {
@@ -2074,6 +2098,11 @@ static int amdgpu_pci_probe(struct pci_dev *pdev,
        size = pci_resource_len(pdev, 0);
        is_fw_fb = amdgpu_is_fw_framebuffer(base, size);
 
+       if (!amdgpu_firmware_installed()) {
+               DRM_ERROR("amdgpu requires firmware installed\n");
+               return -ENODEV;
+       }
+
        /* Get rid of things like offb */
        ret = drm_aperture_remove_conflicting_pci_framebuffers(pdev, &amdgpu_kms_driver);
        if (ret)

diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
index b74cebca1f89e1889accebece0d67afeb927a4ea..c9e4d2fff04df3e29b144fb6723cd2ea521283fa 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@@ -49,6 +49,8 @@
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_vblank.h>
 #include <drm/radeon_drm.h>
+#include <linux/namei.h>
+#include <linux/path.h>
 
 #include "radeon_drv.h"
 #include "radeon.h"
@@ -289,6 +291,28 @@ MODULE_DEVICE_TABLE(pci, pciidlist);
 
 static const struct drm_driver kms_driver;
 
+/* Test that /lib/firmware/radeon 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 radeon_firmware_installed(void)
+{
+#if IS_BUILTIN(CONFIG_DRM_RADEON)
+       /* It may be too early to tell.  Assume it's there. */
+       return true;
+#else
+       struct path path;
+
+       if (kern_path("/lib/firmware/radeon", LOOKUP_DIRECTORY | LOOKUP_FOLLOW,
+                     &path) == 0) {
+               path_put(&path);
+               return true;
+       }
+
+       return false;
+#endif
+}
+
 static int radeon_pci_probe(struct pci_dev *pdev,
                            const struct pci_device_id *ent)
 {
@@ -329,6 +353,12 @@ static int radeon_pci_probe(struct pci_dev *pdev,
        if (vga_switcheroo_client_probe_defer(pdev))
                return -EPROBE_DEFER;
 
+       if ((ent->driver_data & RADEON_FAMILY_MASK) >= CHIP_R600 &&
+           !radeon_firmware_installed()) {
+               DRM_ERROR("radeon kernel modesetting for R600 or later requires firmware installed\n");
+               return -ENODEV;
+       }
+
        /* Get rid of things like offb */
        ret = drm_aperture_remove_conflicting_pci_framebuffers(pdev, &kms_driver);
        if (ret)