[PATCH 2/3] drm/msm: Allocate memory for disp snapshot with kvzalloc()

From: Douglas Anderson
Date: Mon Oct 14 2024 - 12:37:54 EST


With the "drm/msm: add a display mmu fault handler" series [1] we saw
issues in the field where memory allocation was failing when
allocating space for registers in msm_disp_state_dump_regs().
Specifically we were seeing an order 5 allocation fail. It's not
surprising that order 5 allocations will sometimes fail after the
system has been up and running for a while.

There's no need here for contiguous memory. Change the allocation to
kvzalloc() which should make it much less likely to fail.

[1] https://lore.kernel.org/r/20240628214848.4075651-1-quic_abhinavk@xxxxxxxxxxx/

Fixes: 98659487b845 ("drm/msm: add support to take dpu snapshot")
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---

drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c
index bb149281d31f..4d55e3cf570f 100644
--- a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c
+++ b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c
@@ -26,7 +26,7 @@ static void msm_disp_state_dump_regs(u32 **reg, u32 aligned_len, void __iomem *b
end_addr = base_addr + aligned_len;

if (!(*reg))
- *reg = kzalloc(len_padded, GFP_KERNEL);
+ *reg = kvzalloc(len_padded, GFP_KERNEL);

if (*reg)
dump_addr = *reg;
@@ -162,7 +162,7 @@ void msm_disp_state_free(void *data)

list_for_each_entry_safe(block, tmp, &disp_state->blocks, node) {
list_del(&block->node);
- kfree(block->state);
+ kvfree(block->state);
kfree(block);
}

--
2.47.0.rc1.288.g06298d1525-goog