Commit 8cbb2f74 authored by Peter Rosin's avatar Peter Rosin Committed by Greg Kroah-Hartman

mtd: rawnand: atmel: add module param to avoid using dma

[ Upstream commit efc6362c ]

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: default avatarPeter Rosin <>
Reviewed-by: default avatarBoris Brezillon <>
Signed-off-by: default avatarMiquel Raynal <>
Signed-off-by: default avatarSasha Levin <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent a838008b
......@@ -129,6 +129,11 @@
#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 {
......@@ -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;
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