[PATCH v2 09/14] spi: stm32-qspi: Open-code message transfer walk

[Kaitao Cheng]

From: Kaitao Cheng <chengkaitao@xxxxxxxxxx>

A later change will make list_for_each_entry() cache the next element
before entering the loop body. stm32_qspi_transfer_one_message() can
consume the following transfer as part of the current operation and then
advance the loop cursor to that entry.

Keep the transfer walk open-coded so the loop step observes that cursor
update and skips the consumed transfer. This preserves the existing
message sequencing semantics and prepares the code for the list iterator
update.

Signed-off-by: Kaitao Cheng <chengkaitao@xxxxxxxxxx>
---
 drivers/spi/spi-stm32-qspi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-stm32-qspi.c b/drivers/spi/spi-stm32-qspi.c
index df1bbacec90a..27d82a578c9f 100644
--- a/drivers/spi/spi-stm32-qspi.c
+++ b/drivers/spi/spi-stm32-qspi.c
@@ -577,7 +577,10 @@ static int stm32_qspi_transfer_one_message(struct spi_controller *ctrl,
 
 	gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), true);
 
-	list_for_each_entry(transfer, &msg->transfers, transfer_list) {
+	for (transfer = list_first_entry(&msg->transfers,
+					 typeof(*transfer), transfer_list);
+	     !list_entry_is_head(transfer, &msg->transfers, transfer_list);
+	     transfer = list_next_entry(transfer, transfer_list)) {
 		u8 dummy_bytes = 0;
 
 		memset(&op, 0, sizeof(op));
-- 
2.43.0