[PATCH] mtd: spi-nor: add cmdlineparts to intel-spi

[PATCH] mtd: spi-nor: add cmdlineparts to intel-spi

[Ronald G. Minnich]

On Intel platforms, the usable SPI area is located several
MiB in from the start, to leave room for descriptors and
the Management Engine binary. Further, not all the remaining
space can be used, as the last 16 MiB contains firmware.

To make the SPI usable for mtdblock and other devices,
it is necessary to enable command line partitions so the
middle usable region can be specified.

Add a part_probes array which includes only "cmdelineparts",
and change to mtd_device_parse_register to use this part_probes.

Signed-off-by: Ronald G. Minnich <rminnich@google.com>
---
 drivers/mtd/spi-nor/controllers/intel-spi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/controllers/intel-spi.c b/drivers/mtd/spi-nor/controllers/intel-spi.c
index 61d2a0ad2131..132129e89d07 100644
--- a/drivers/mtd/spi-nor/controllers/intel-spi.c
+++ b/drivers/mtd/spi-nor/controllers/intel-spi.c
@@ -894,6 +894,8 @@ static const struct spi_nor_controller_ops intel_spi_controller_ops = {
 	.erase = intel_spi_erase,
 };
 
+static const char * const part_probes[] = { "cmdlinepart", NULL };
+
 struct intel_spi *intel_spi_probe(struct device *dev,
 	struct resource *mem, const struct intel_spi_boardinfo *info)
 {
@@ -941,7 +943,8 @@ struct intel_spi *intel_spi_probe(struct device *dev,
 	if (!ispi->writeable || !writeable)
 		ispi->nor.mtd.flags &= ~MTD_WRITEABLE;
 
-	ret = mtd_device_register(&ispi->nor.mtd, &part, 1);
+	ret = mtd_device_parse_register(&ispi->nor.mtd, part_probes,
+				       NULL, &part, 1);
 	if (ret)
 		return ERR_PTR(ret);
 
-- 
2.26.1.301.g55bc3eb7cb9-goog

Re: [PATCH] mtd: spi-nor: add cmdlineparts to intel-spi

[Mika Westerberg]

On Thu, Apr 16, 2020 at 09:28:28AM -0700, Ronald G. Minnich wrote:
> On Intel platforms, the usable SPI area is located several
> MiB in from the start, to leave room for descriptors and
> the Management Engine binary. Further, not all the remaining
> space can be used, as the last 16 MiB contains firmware.
> 
> To make the SPI usable for mtdblock and other devices,
> it is necessary to enable command line partitions so the
> middle usable region can be specified.
> 
> Add a part_probes array which includes only "cmdelineparts",
> and change to mtd_device_parse_register to use this part_probes.
> 
> Signed-off-by: Ronald G. Minnich <rminnich@google.com>

I guess the $subject should be something like:

  mtd: spi-nor: controllers: intel-spi: Add support for command line partitions

The patch itself looks good to me,

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>