From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Hellstrom Subject: [PATCH] drm/ttm: Don't move non-existing data Date: Sun, 17 Nov 2013 23:30:38 -0800 Message-ID: <1384759838-3501-1-git-send-email-thellstrom@vmware.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp-outbound-1.vmware.com (smtp-outbound-1.vmware.com [208.91.2.12]) by gabe.freedesktop.org (Postfix) with ESMTP id 99CBCFD774 for ; Sun, 17 Nov 2013 23:30:51 -0800 (PST) Received: from sc9-mailhost1.vmware.com (sc9-mailhost1.vmware.com [10.113.161.71]) by smtp-outbound-1.vmware.com (Postfix) with ESMTP id 329DF2AAB4 for ; Sun, 17 Nov 2013 23:30:51 -0800 (PST) Received: from zcs-prod-ext-mta-2.vmware.com (zcs-prod-ext-mta-2.vmware.com [10.113.62.224]) by sc9-mailhost1.vmware.com (Postfix) with ESMTP id 2E5A7183F1 for ; Sun, 17 Nov 2013 23:30:51 -0800 (PST) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: jakob@vmware.com, dri-devel@lists.freedesktop.org Cc: Thomas Hellstrom , linux-graphics-maintainer@vmware.com List-Id: dri-devel@lists.freedesktop.org If ttm_bo_move_memcpy was instructed to move a non-populated ttm to io memory, it would first populate the ttm, then move the data and then destroy the ttm. That's stupid. However, some drivers might have relied on this to clear io memory from old stuff. So instead of a NOP, which would be the most efficient, just clear the destination. Signed-off-by: Thomas Hellstrom --- drivers/gpu/drm/ttm/ttm_bo_util.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c index 4834c46..15b86a9 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_util.c +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c @@ -350,10 +350,13 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo, goto out2; /* - * Move nonexistent data. NOP. + * Don't move nonexistent data. Clear destination instead. */ - if (old_iomap == NULL && ttm == NULL) + if (old_iomap == NULL && + (ttm == NULL || ttm->state == tt_unpopulated)) { + memset_io(new_iomap, 0, new_mem->num_pages*PAGE_SIZE); goto out2; + } /* * TTM might be null for moves within the same region. -- 1.7.10.4