From: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> commit bf8975837dac156c33a4d15d46602700998cb6dd upstream. We hardcode the maximum number of shared fences to 4, instead of respecting num_fences. Use a minimum of 4, but more if num_fences is higher. This seems to have been an oversight when first implementing the api. Fixes: 04a5faa8cbe5 ("reservation: update api and add some helpers") Cc: <stable@xxxxxxxxxxxxxxx> # v3.17+ Reported-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@xxxxxxxxx> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Reviewed-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20201124115707.406917-1-maarten.lankhorst@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/dma-buf/dma-resv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -200,7 +200,7 @@ int dma_resv_reserve_shared(struct dma_r max = max(old->shared_count + num_fences, old->shared_max * 2); } else { - max = 4; + max = max(4ul, roundup_pow_of_two(num_fences)); } new = dma_resv_list_alloc(max);