Re: [PATCH v2 2/2] mtd: spi-nor: Mask out fast read if not requested in DT

Hi Pratyush,

On Fri, Jul 30, 2021 at 3:31 PM Pratyush Yadav p.yadav@ti.com wrote:

On 30/07/21 03:20PM, Bin Meng wrote:

...

The DT bindings of "jedec,spi-nor" [1] defines "m25p,fast-read" property to indicate that "fast read" opcode can be used to read data from the chip instead of the usual "read" opcode.

If this property is not present in DT, mask out fast read in spi_nor_init_params(). This change mirrors the same logic in spi_nor_info_init_params() in drivers/mtd/spi-nor/core.c in the Linux kernel v5.14-rc3.

[1] Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml in the kernel tree

Signed-off-by: Bin Meng bmeng.cn@gmail.com

---

Changes in v2:

• Guard changes with CONFIG_IS_ENABLED(DM_SPI)

Hehe, I just commented about this on your v1, and I see the v2 in my inbox already ;-)

So this will make sure that dev_ofnode() will be valid, right?

This is to avoid build error for non-DM_SPI platforms.

For dev_ofnode() I think it's always valid, as spi_nor_init_params() is called by spi_nor_scan() in sf_probe.c which does not support OF_PLATDATA.

...

drivers/mtd/spi/spi-nor-core.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c index c8c3bdd890..d5d905fa5a 100644 --- a/drivers/mtd/spi/spi-nor-core.c +++ b/drivers/mtd/spi/spi-nor-core.c @@ -2604,18 +2604,28 @@ static int spi_nor_init_params(struct spi_nor *nor, params->size = info->sector_size * info->n_sectors; params->page_size = info->page_size;

• if (!(info->flags & SPI_NOR_NO_FR)) {
  

•         /* Default to Fast Read for DT and non-DT platform devices. */
  

•         params->hwcaps.mask |= SNOR_HWCAPS_READ_FAST;
  

•         /* Mask out Fast Read if not requested at DT instantiation. */
  

+#if CONFIG_IS_ENABLED(DM_SPI)

•         if (!ofnode_read_bool(dev_ofnode(nor->spi->dev),
  

Let's avoid the #if here and do

if (CONFIG_IS_ENABLED(DM_SPI) && !ofnode_read_bool())

This does not work because nor->spi->dev has to be inside CONFIG_IS_ENABLED(DM_SPI) as well.

...

•                               "m25p,fast-read"))
  

•                 params->hwcaps.mask &= ~SNOR_HWCAPS_READ_FAST;
  

+#endif

• }
  

• /* (Fast) Read settings. */
  params->hwcaps.mask |= SNOR_HWCAPS_READ;
  spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ],
                            0, 0, SPINOR_OP_READ,
                            SNOR_PROTO_1_1_1);
  
  

• if (!(info->flags & SPI_NOR_NO_FR)) {
  

•         params->hwcaps.mask |= SNOR_HWCAPS_READ_FAST;
  

• if (params->hwcaps.mask & SNOR_HWCAPS_READ_FAST)
          spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ_FAST],
                                    0, 8, SPINOR_OP_READ_FAST,
                                    SNOR_PROTO_1_1_1);
  

• }
  
  if (info->flags & SPI_NOR_DUAL_READ) {
          params->hwcaps.mask |= SNOR_HWCAPS_READ_1_1_2;
  

Regards, Bin