Messages in this thread | | | Date | Tue, 30 Jun 2015 10:42:54 -0500 | From | Graham Moore <> | Subject | Re: [PATCH] mtd: spi-nor: Only set Micron quad-read mode when controller in 4-lane TX mode |
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On 06/30/2015 06:17 AM, Mike Looijmans wrote: > Micron QUAD mode expects command, address and data on 4 lanes instead of just > one for command (extended SPI mode). This requires the controller to be in a > special mode, so check first if the controller could be in that mode. If a > controller does not have the SPI_TX_QUAD mode set, this setting has no chance > of being valid at all, so don't try to enable it then, and just keep using > the extended SPI mode. > > Tested on a Zynq 7000 with a n25q256a flash chip, this failed to function > because of the introduction of: > "driver:mtd:spi-nor: Add quad I/O support for Micron spi nor" > This commit sets QUAD mode for most Micron chips without asking the controller > whether it's possible to do so, and without telling the controller that a > different mode is required, so it couldn't work. > > Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl> > --- > drivers/mtd/spi-nor/spi-nor.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c > index e8f6131..10ba94f 100644 > --- a/drivers/mtd/spi-nor/spi-nor.c > +++ b/drivers/mtd/spi-nor/spi-nor.c > @@ -1398,6 +1398,8 @@ static int set_quad_mode(struct spi_nor *nor, struct flash_info *info) > } > return status; > case CFI_MFR_ST: > + if (!(nor->spi->mode & SPI_TX_QUAD)) > + return 0;
This is a great idea, but what codebase are you working from? My l2-mtd tree doesn't have a 'spi' member of spi_nor, and this case statement is around line 977, not 1398.
> status = micron_quad_enable(nor); > if (status) { > dev_err(nor->dev, "Micron quad-read not enabled\n"); >
Regards, Graham
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