Messages in this thread | | | Date | Wed, 1 Jul 2015 07:40:40 +0200 | From | Mike Looijmans <> | Subject | Re: [PATCH] mtd: spi-nor: Only set Micron quad-read mode when controller in 4-lane TX mode |
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On 30-06-15 17:42, Graham Moore wrote: > 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.
I was working from the Xilinx kernel tree, and there's a lot of changes there. The one that added the "struct spi_device* spi" to the nor struct is: 63697f5cf9a6201556947ef0ea29442843e5ba61 mtd: spi-nor: Changes for stacked and parallel
>> status = micron_quad_enable(nor); >> if (status) { >> dev_err(nor->dev, "Micron quad-read not enabled\n"); >>
Kind regards,
Mike Looijmans System Expert
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