[PATCH] drm/xe/gsc: Don't create mei-gscfi aux device while running in VF mode

[Vivek Kasireddy]

While running in SR-IOV VF mode inside a Guest Virtual Machine (VM),
we do not have to initialize and enable the mei-gscfi auxiliary
device. This is because communication with the GSC/CSC firmware,
which is the main purpose of the aux device, would not work in
this mode (as relevant MMIO registers cannot be accessed), and
can result in the following errors while loading the Xe driver:

[  762.274208] mei_gsc xe.mei-gscfi.24: H_RST is not set = 0x00000000
[  764.299203] mei_gsc xe.mei-gscfi.24: wait hw ready failed
[  764.300334] mei_gsc xe.mei-gscfi.24: hw_start failed ret = -62 fw status = 00000000 00000000 00000000 00000000 00000000 00000000
[  768.333706] mei_gsc xe.mei-gscfi.24: reset: reached maximal consecutive resets: disabling the device
[  768.334466] mei_gsc xe.mei-gscfi.24: reset failed ret = -19
[  768.334941] mei_gsc xe.mei-gscfi.24: link layer initialization failed.
[  768.335346] mei_gsc xe.mei-gscfi.24: init hw failure.

Cc: Alexander Usyskin <alexander.usyskin at intel.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy at intel.com>
---
v2: Reword commit message to clarify that the mei-gscfi aux device
    do not have to be created only while running in SR-IOV VF mode.
---
 drivers/gpu/drm/xe/xe_heci_gsc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_heci_gsc.c b/drivers/gpu/drm/xe/xe_heci_gsc.c
index 6d7b62724126..eb94fcb3f03b 100644
--- a/drivers/gpu/drm/xe/xe_heci_gsc.c
+++ b/drivers/gpu/drm/xe/xe_heci_gsc.c
@@ -13,6 +13,7 @@
 #include "xe_heci_gsc.h"
 #include "regs/xe_gsc_regs.h"
 #include "xe_platform_types.h"
+#include "xe_sriov.h"
 #include "xe_survivability_mode.h"
 
 #define GSC_BAR_LENGTH  0x00000FFC
@@ -176,6 +177,9 @@ int xe_heci_gsc_init(struct xe_device *xe)
 	if (!xe->info.has_heci_gscfi && !xe->info.has_heci_cscfi)
 		return 0;
 
+	if (IS_SRIOV_VF(xe))
+		return 0;
+
 	heci_gsc->irq = -1;
 
 	if (xe->info.platform == XE_BATTLEMAGE) {
-- 
2.49.0