[PATCH v2 2/2] vfio/nvgrace-gpu: Drop the usemem length check in open_device

[Andrea Parri <parri.andrea@gmail.com>]

nvgrace_gpu_open_device() sets up the fake BAR registers and remap_lock
only when usemem.memlength is nonzero.  The check exists for fallback
mode, which used to share this open path.  Fallback mode now has its own
open_device, so only devices with ACPI memory properties reach this one.

For those devices usemem.memlength is never zero: an empty region from
nvgrace_gpu_fetch_memory_property() selects fallback mode, and probe
fails when nvgrace_gpu_init_nvdev_struct() rounds usemem down to
nothing.  Do the setup unconditionally.

Assisted-by: LLM
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
---
v2: New patch

 drivers/vfio/pci/nvgrace-gpu/main.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/vfio/pci/nvgrace-gpu/main.c b/drivers/vfio/pci/nvgrace-gpu/main.c
index 208463c218088..8dc792b4fe7ac 100644
--- a/drivers/vfio/pci/nvgrace-gpu/main.c
+++ b/drivers/vfio/pci/nvgrace-gpu/main.c
@@ -185,10 +185,8 @@ static int nvgrace_gpu_open_device(struct vfio_device *core_vdev)
 	if (ret)
 		return ret;
 
-	if (nvdev->usemem.memlength) {
-		nvgrace_gpu_init_fake_bar_emu_regs(core_vdev);
-		mutex_init(&nvdev->remap_lock);
-	}
+	nvgrace_gpu_init_fake_bar_emu_regs(core_vdev);
+	mutex_init(&nvdev->remap_lock);
 
 	/*
 	 * GPU readiness is checked by reading the BAR0 registers.
-- 
2.53.0