[PATCH net 1/1] net: ipa: pass the correct size when freeing DMA memory

From: Alex Elder
Date: Thu Dec 03 2020 - 16:51:52 EST


When the coherent memory is freed in gsi_trans_pool_exit_dma(), we
are mistakenly passing the size of a single element in the pool
rather than the actual allocated size. Fix this bug.

Fixes: 9dd441e4ed575 ("soc: qcom: ipa: GSI transactions")
Reported-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Tested-by: Sujit Kautkar <sujitka@xxxxxxxxxxxx>
Signed-off-by: Alex Elder <elder@xxxxxxxxxx>
---
drivers/net/ipa/gsi_trans.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ipa/gsi_trans.c b/drivers/net/ipa/gsi_trans.c
index e8599bb948c08..6c3ed5b17b80c 100644
--- a/drivers/net/ipa/gsi_trans.c
+++ b/drivers/net/ipa/gsi_trans.c
@@ -156,6 +156,9 @@ int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool,
/* The allocator will give us a power-of-2 number of pages. But we
* can't guarantee that, so request it. That way we won't waste any
* memory that would be available beyond the required space.
+ *
+ * Note that gsi_trans_pool_exit_dma() assumes the total allocated
+ * size is exactly (count * size).
*/
total_size = get_order(total_size) << PAGE_SHIFT;

@@ -175,7 +178,9 @@ int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool,

void gsi_trans_pool_exit_dma(struct device *dev, struct gsi_trans_pool *pool)
{
- dma_free_coherent(dev, pool->size, pool->base, pool->addr);
+ size_t total_size = pool->count * pool->size;
+
+ dma_free_coherent(dev, total_size, pool->base, pool->addr);
memset(pool, 0, sizeof(*pool));
}

--
2.20.1