Commit 970a5ee4 authored by Ben Skeggs's avatar Ben Skeggs
Browse files

drm/nouveau/kms/nv50-: also flush fb writes when rewinding push buffer 



Should hopefully fix a regression some people have been seeing since EVO
push buffers were moved to VRAM by default on Pascal GPUs.

Fixes: d00ddd9d ("drm/nouveau/kms/nv50-: allocate push buffers in vidmem on pascal")
Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
Cc: <stable@vger.kernel.org> # 4.19+
parent 4ac0a807

drivers/gpu/drm/nouveau/dispnv50/disp.c

+18 −11
Original line number Diff line number Diff line
@@ -198,6 +198,22 @@ nv50_dmac_create(struct nvif_device *device, struct nvif_object *disp, 
/******************************************************************************

 * EVO channel helpers

 *****************************************************************************/

static void

evo_flush(struct nv50_dmac *dmac)

{

	/* Push buffer fetches are not coherent with BAR1, we need to ensure

	 * writes have been flushed right through to VRAM before writing PUT.

	 */

	if (dmac->push.type & NVIF_MEM_VRAM) {

		struct nvif_device *device = dmac->base.device;

		nvif_wr32(&device->object, 0x070000, 0x00000001);

		nvif_msec(device, 2000,

			if (!(nvif_rd32(&device->object, 0x070000) & 0x00000002))

				break;

		);

	}

}



u32 *

evo_wait(struct nv50_dmac *evoc, int nr)

{
@@ -208,6 +224,7 @@ evo_wait(struct nv50_dmac *evoc, int nr) 
	mutex_lock(&dmac->lock);

	if (put + nr >= (PAGE_SIZE / 4) - 8) {

		dmac->ptr[put] = 0x20000000;

		evo_flush(dmac);



		nvif_wr32(&dmac->base.user, 0x0000, 0x00000000);

		if (nvif_msec(device, 2000,
@@ -230,17 +247,7 @@ evo_kick(u32 *push, struct nv50_dmac *evoc) 
{

	struct nv50_dmac *dmac = evoc;



	/* Push buffer fetches are not coherent with BAR1, we need to ensure

	 * writes have been flushed right through to VRAM before writing PUT.

	 */

	if (dmac->push.type & NVIF_MEM_VRAM) {

		struct nvif_device *device = dmac->base.device;

		nvif_wr32(&device->object, 0x070000, 0x00000001);

		nvif_msec(device, 2000,

			if (!(nvif_rd32(&device->object, 0x070000) & 0x00000002))

				break;

		);

	}

	evo_flush(dmac);



	nvif_wr32(&dmac->base.user, 0x0000, (push - dmac->ptr) << 2);

	mutex_unlock(&dmac->lock);