[U-Boot] [PATCH] mmc: dw_mmc: Handle return value from bounce_buffer_start()

[Marek Vasut]

The bounce_buffer_start() can return -ENOMEM in case memory allocation
failed. However, in that case, the bounce buffer address is the same as
the possibly unaligned input address, and the cache maintenance operations
were not applied to this address. This could cause subtle problems. Add
handling for the bounce_buffer_start() return value to prevent such a
problem from happening.

Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Jaehoon Chung <jh80.chung at samsung.com>
Cc: Simon Glass <sjg at chromium.org>
---
 drivers/mmc/dw_mmc.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
index 8278f1dacb..72570235cb 100644
--- a/drivers/mmc/dw_mmc.c
+++ b/drivers/mmc/dw_mmc.c
@@ -261,14 +261,20 @@ static int dwmci_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
 			dwmci_wait_reset(host, DWMCI_CTRL_FIFO_RESET);
 		} else {
 			if (data->flags == MMC_DATA_READ) {
-				bounce_buffer_start(&bbstate, (void*)data->dest,
+				ret = bounce_buffer_start(&bbstate,
+						(void*)data->dest,
 						data->blocksize *
 						data->blocks, GEN_BB_WRITE);
 			} else {
-				bounce_buffer_start(&bbstate, (void*)data->src,
+				ret = bounce_buffer_start(&bbstate,
+						(void*)data->src,
 						data->blocksize *
 						data->blocks, GEN_BB_READ);
 			}
+
+			if (ret)
+				return ret;
+
 			dwmci_prepare_data(host, data, cur_idmac,
 					   bbstate.bounce_buffer);
 		}
-- 
2.20.1