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authorPeter Rosin <peda@axentia.se>2018-03-29 15:10:54 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-10-03 17:00:50 -0700
commit8cbb2f74c0939901d8b96b8fa820afe619790758 (patch)
tree2bdcc9d15aec6d932a640364bae1e2107c8b6ca4 /drivers/mtd
parenta838008bb11f96f14bfc48a22e88116eb74351ab (diff)
mtd: rawnand: atmel: add module param to avoid using dma
[ Upstream commit efc6362c6f8c1e74b340e2611f1b35e7d557ce7b ] On a sama5d31 with a Full-HD dual LVDS panel (132MHz pixel clock) NAND flash accesses have a tendency to cause display disturbances. Add a module param to disable DMA from the NAND controller, since that fixes the display problem for me. Signed-off-by: Peter Rosin <peda@axentia.se> Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/nand/atmel/nand-controller.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/mtd/nand/atmel/nand-controller.c b/drivers/mtd/nand/atmel/nand-controller.c
index 68c9d98a3347..148744418e82 100644
--- a/drivers/mtd/nand/atmel/nand-controller.c
+++ b/drivers/mtd/nand/atmel/nand-controller.c
@@ -129,6 +129,11 @@
#define DEFAULT_TIMEOUT_MS 1000
#define MIN_DMA_LEN 128
+static bool atmel_nand_avoid_dma __read_mostly;
+
+MODULE_PARM_DESC(avoiddma, "Avoid using DMA");
+module_param_named(avoiddma, atmel_nand_avoid_dma, bool, 0400);
+
enum atmel_nand_rb_type {
ATMEL_NAND_NO_RB,
ATMEL_NAND_NATIVE_RB,
@@ -1975,7 +1980,7 @@ static int atmel_nand_controller_init(struct atmel_nand_controller *nc,
return ret;
}
- if (nc->caps->has_dma) {
+ if (nc->caps->has_dma && !atmel_nand_avoid_dma) {
dma_cap_mask_t mask;
dma_cap_zero(mask);