[PATCH] spi: spi-topcliff-pch: Replace GFP_ATOMIC with GFP_KERNEL in pch_spi_handle_dma

From: Jia-Ju Bai
Date: Tue Apr 10 2018 - 05:09:00 EST


pch_spi_handle_dma() is never called in atomic context.
This function is only called by pch_spi_process_messages().
pch_spi_process_messages() is only set as a parameter of INIT_WORK() in
pch_spi_pd_probe().

Despite never getting called from atomic context,
pch_spi_handle_dma() calls kcalloc() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.

Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
drivers/spi/spi-topcliff-pch.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index 97d1375..dc93ca9 100644
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -1007,7 +1007,7 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
spin_unlock_irqrestore(&data->lock, flags);

/* RX */
- dma->sg_rx_p = kcalloc(num, sizeof(*dma->sg_rx_p), GFP_ATOMIC);
+ dma->sg_rx_p = kcalloc(num, sizeof(*dma->sg_rx_p), GFP_KERNEL);
sg_init_table(dma->sg_rx_p, num); /* Initialize SG table */
/* offset, length setting */
sg = dma->sg_rx_p;
@@ -1067,7 +1067,7 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
head = 0;
}

- dma->sg_tx_p = kcalloc(num, sizeof(*dma->sg_tx_p), GFP_ATOMIC);
+ dma->sg_tx_p = kcalloc(num, sizeof(*dma->sg_tx_p), GFP_KERNEL);
sg_init_table(dma->sg_tx_p, num); /* Initialize SG table */
/* offset, length setting */
sg = dma->sg_tx_p;
--
1.9.1