From bf8975837dac156c33a4d15d46602700998cb6dd Mon Sep 17 00:00:00 2001
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Date: Tue, 24 Nov 2020 12:57:07 +0100
Subject: [PATCH] dma-buf/dma-resv: Respect num_fences when initializing the shared fence list.
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Git-commit: bf8975837dac156c33a4d15d46602700998cb6dd
Patch-mainline: v5.11-rc1
References: git-fixes

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@vger.kernel.org> # v3.17+
Reported-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201124115707.406917-1-maarten.lankhorst@linux.intel.com
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/dma-buf/dma-resv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index bb5a42b10c29..6ddbeb5dfbf6 100644
--- 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_resv *obj, unsigned int num_fences)
 			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);
-- 
2.26.2