From 7995d74ab297e4f5526c8df70007e1e39f0d1f5c Mon Sep 17 00:00:00 2001
From: Alexander Stein <alexander.stein@systec-electronic.com>
Date: Wed, 26 Feb 2014 16:31:19 +0100
Subject: [PATCH] spi-topcliff-pch: Fix probing when DMA mode is used
If during registering SPI master due to SPI device probing a SPI transfer
is issued the DMA buffers are not allocated yet.
This fixes the following oops:
pch_spi 0000:02:0c.1: enabling device (0000 -> 0002)
pch_spi 0000:02:0c.1: master is unqueued, this is deprecated
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<c125aa05>] pch_spi_handle_dma+0x15c/0x6f4
[...]
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
---
drivers/spi/spi-topcliff-pch.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index 3383008ce04d4..88eb57e858b37 100644
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -1452,6 +1452,11 @@ static int pch_spi_pd_probe(struct platform_device *plat_dev)
pch_spi_set_master_mode(master);
+ if (use_dma) {
+ dev_info(&plat_dev->dev, "Use DMA for data transfers\n");
+ pch_alloc_dma_buf(board_dat, data);
+ }
+
ret = spi_register_master(master);
if (ret != 0) {
dev_err(&plat_dev->dev,
@@ -1459,14 +1464,10 @@ static int pch_spi_pd_probe(struct platform_device *plat_dev)
goto err_spi_register_master;
}
- if (use_dma) {
- dev_info(&plat_dev->dev, "Use DMA for data transfers\n");
- pch_alloc_dma_buf(board_dat, data);
- }
-
return 0;
err_spi_register_master:
+ pch_free_dma_buf(board_dat, data);
free_irq(board_dat->pdev->irq, data);
err_request_irq:
pch_spi_free_resources(board_dat, data);
--
2.39.5