On Wed, Dec 21, 2016 at 10:38:41PM +0100, Christian Hemp wrote: > The function "nand_enable_edo_mode" changed the NAND clk rate, without turning > it off. In this case it is posible to get the following errors: > MXS NAND: Error sending command > MXS NAND: Error sending command > MXS NAND: DMA read error > > This can be fixed if the NAND clk is disabled before we change the clk > rate. > > Tested with: > nand: NAND device: Manufacturer ID: 0x2c, Chip ID: 0xdc (Micron > MT29F4G08ABADAWP), 512MiB, page size: 2048, OOB size: 64 > > Signed-off-by: Christian Hemp <c.hemp@xxxxxxxxx> > --- > drivers/mtd/nand/nand_mxs.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/mtd/nand/nand_mxs.c b/drivers/mtd/nand/nand_mxs.c > index cba0bee..ce79bca 100644 > --- a/drivers/mtd/nand/nand_mxs.c > +++ b/drivers/mtd/nand/nand_mxs.c > @@ -2047,7 +2047,9 @@ static int mxs_nand_enable_edo_mode(struct mxs_nand_info *info) > nand->select_chip(mtd, -1); > > /* [3] set the main IO clock, 100MHz for mode 5, 80MHz for mode 4. */ > + clk_disable(info->clk); > clk_set_rate(info->clk, (mode == 5) ? 100000000 : 80000000); > + clk_enable(info->clk); Calling clk_disable doesn't guarantee that the clock is actually disabled. If there's another user of the same clock then clk_disable will only decrease the usage counter. I think if possible we should fix this in the clock driver instead. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
