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 <[email protected]> --- drivers/mtd/nand/raw/atmel/nand-controller.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c index b2f00b398490..2ff7a77c7b8e 100644 --- a/drivers/mtd/nand/raw/atmel/nand-controller.c +++ b/drivers/mtd/nand/raw/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, @@ -1977,7 +1982,7 @@ 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); -- 2.11.0
