On Thu, Jan 20, 2022 at 12:30:49PM +0100, Piorkowski, Piotr wrote:
From: Piotr Piórkowski <[email protected]>
For proper operation of i915 we need usable PCI BARs:
- GTTMMADDR BAR 0 (1 for GEN2)
- GFXMEM BAR 2.
Lets check before we start the i915 probe that these BARs are set,
and that they have a size greater than 0.
Signed-off-by: Piotr Piórkowski <[email protected]>
Cc: Michal Wajdeczko <[email protected]>
Cc: Jani Nikula <[email protected]>
This sounds reasonable to me... should catch issues in which the BIOS
didn't assign resources properly, PCI subsystem tried to reassign them
and we ended up left withou a BAR.
+Matt Auld who is working on small BAR recovery... slightly related.
Does this look ok?
Acked-by: Lucas De Marchi <[email protected]>
thanks
Lucas De Marchi
---
drivers/gpu/drm/i915/i915_pci.c | 33 +++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_pci_config.h | 5 ++++
2 files changed, 38 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c
index 8261b6455747..ad60c69d9dd8 100644
--- a/drivers/gpu/drm/i915/i915_pci.c
+++ b/drivers/gpu/drm/i915/i915_pci.c
@@ -29,6 +29,8 @@
#include "i915_drv.h"
#include "i915_pci.h"
+#include "intel_pci_config.h"
+
#define PLATFORM(x) .platform = (x)
#define GEN(x) \
.graphics.ver = (x), \
@@ -1181,6 +1183,34 @@ static bool force_probe(u16 device_id, const char
*devices)
return ret;
}
+static bool __pci_resource_valid(struct pci_dev *pdev, int bar)
+{
+ if (!pci_resource_flags(pdev, bar))
+ return false;
+
+ if (pci_resource_flags(pdev, bar) & IORESOURCE_UNSET)
+ return false;
+
+ if (!pci_resource_len(pdev, bar))
+ return false;
+
+ return true;
+}
+
+static bool intel_bars_valid(struct pci_dev *pdev, struct intel_device_info
*intel_info)
+{
+ const int gttmmaddr_bar = intel_info->graphics.ver == 2 ?
GEN2_GTTMMADR_BAR : GTTMMADR_BAR;
+ const int gfxmem_bar = GFXMEM_BAR;
+
+ if (!__pci_resource_valid(pdev, gttmmaddr_bar))
+ return false;
+
+ if (!__pci_resource_valid(pdev, gfxmem_bar))
+ return false;
+
+ return true;
+}
+
static int i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
struct intel_device_info *intel_info =
@@ -1206,6 +1236,9 @@ static int i915_pci_probe(struct pci_dev *pdev, const
struct pci_device_id *ent)
if (PCI_FUNC(pdev->devfn))
return -ENODEV;
+ if (!intel_bars_valid(pdev, intel_info))
+ return -ENODEV;
+
/* Detect if we need to wait for other drivers early on */
if (intel_modeset_probe_defer(pdev))
return -EPROBE_DEFER;
diff --git a/drivers/gpu/drm/i915/intel_pci_config.h
b/drivers/gpu/drm/i915/intel_pci_config.h
index 12cd9d4f23de..c08fd5d48ada 100644
--- a/drivers/gpu/drm/i915/intel_pci_config.h
+++ b/drivers/gpu/drm/i915/intel_pci_config.h
@@ -6,6 +6,11 @@
#ifndef __INTEL_PCI_CONFIG_H__
#define __INTEL_PCI_CONFIG_H__
+/* PCI BARs */
+#define GTTMMADR_BAR 0
+#define GEN2_GTTMMADR_BAR 1
+#define GFXMEM_BAR 2
+
/* BSM in include/drm/i915_drm.h */
#define MCHBAR_I915 0x44
--
2.25.1
