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 <peda@axentia.se>
Reviewed-by: default avatarBoris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: default avatarSasha Levin <alexander.levin@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a838008b
......@@ -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);
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment