drm/msm: fix handling of cmdstream offset

BugLink: https://bugs.launchpad.net/bugs/1837257
[ Upstream commit 47e7f506ee6590ceb2efa1f08aca7f9f2ee5c1d3 ]

Userspace hasn't used submit cmds with submit_offset != 0 for a while,
but this starts cropping up again with cmdstream sub-buffer-allocation
in libdrm_freedreno.

Doesn't do much good to increment the buf ptr before assigning it.

Fixes: 78b8e5b847b4 drm/msm: dump a rd GPUADDR header for all buffers in the command
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/gpu/drm/msm/msm_rd.c b/drivers/gpu/drm/msm/msm_rd.c
index 3aa8a8576abea8323a4c30534837a3defcac9b17..f7a0edea4705bcf5a50e2cf0d9211e7422de2ef7 100644 (file)
--- a/drivers/gpu/drm/msm/msm_rd.c
+++ b/drivers/gpu/drm/msm/msm_rd.c
@@ -316,10 +316,11 @@ static void snapshot_buf(struct msm_rd_state *rd,
                uint64_t iova, uint32_t size)
 {
        struct msm_gem_object *obj = submit->bos[idx].obj;
+       unsigned offset = 0;
        const char *buf;
 
        if (iova) {
-               buf += iova - submit->bos[idx].iova;
+               offset = iova - submit->bos[idx].iova;
        } else {
                iova = submit->bos[idx].iova;
                size = obj->base.size;
@@ -340,6 +341,8 @@ static void snapshot_buf(struct msm_rd_state *rd,
        if (IS_ERR(buf))
                return;
 
+       buf += offset;
+
        rd_write_section(rd, RD_BUFFER_CONTENTS, buf, size);
 
        msm_gem_put_vaddr(&obj->base);