Message ID | 20200929095951.1575658-2-tudor.ambarus@microchip.com |
---|---|
State | Superseded |
Delegated to: | Ambarus Tudor |
Headers | show |
Series | mtd: spi-nor: Tackle stateful modes | expand |
On 9/29/20 3:29 PM, Tudor Ambarus wrote: > We don't want to enter a stateful mode, where a X-X-X I/O mode > is entered by setting a non-volatile bit, because in case of a > reset or a crash, once in the non-volatile mode, we may not be able > to recover in bootloaders and we may break the SPI NOR boot. > > Forbid by default the I/O modes that are set via a non-volatile bit. > > SPI_NOR_IO_MODE_EN_VOLATILE should be set just for the flashes that > don't define the optional SFDP SCCR Map, so that we don't pollute the > flash info flags. > I would make this SPI_NOR_IO_MODE_EN_NON_VOLATILE. Because flashes with volatile bits to change IO modes are more common than non volatile ones and above change makes its easier to spot such quirky flashes. > Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> > --- > drivers/mtd/spi-nor/core.c | 6 ++++++ > drivers/mtd/spi-nor/core.h | 6 ++++++ > 2 files changed, 12 insertions(+) > > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > index 34edfcf33172..c149b318e2e8 100644 > --- a/drivers/mtd/spi-nor/core.c > +++ b/drivers/mtd/spi-nor/core.c > @@ -3089,6 +3089,9 @@ static int spi_nor_octal_dtr_enable(struct spi_nor *nor, bool enable) > nor->write_proto == SNOR_PROTO_8_8_8_DTR)) > return 0; > > + if (!(nor->flags & SNOR_F_IO_MODE_EN_VOLATILE)) > + return 0; > + > ret = nor->params->octal_dtr_enable(nor, enable); > if (ret) > return ret; > @@ -3474,6 +3477,9 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, > if (info->flags & SPI_NOR_4B_OPCODES) > nor->flags |= SNOR_F_4B_OPCODES; > > + if (info->flags & SPI_NOR_IO_MODE_EN_VOLATILE) > + nor->flags |= SNOR_F_IO_MODE_EN_VOLATILE; > + > ret = spi_nor_set_addr_width(nor); > if (ret) > return ret; > diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h > index 10dc03506f93..c2755c82f978 100644 > --- a/drivers/mtd/spi-nor/core.h > +++ b/drivers/mtd/spi-nor/core.h > @@ -27,6 +27,7 @@ enum spi_nor_option_flags { > SNOR_F_HAS_4BIT_BP = BIT(12), > SNOR_F_HAS_SR_BP3_BIT6 = BIT(13), > SNOR_F_SOFT_RESET = BIT(14), > + SNOR_F_IO_MODE_EN_VOLATILE = BIT(15), > }; > > struct spi_nor_read_command { > @@ -323,6 +324,11 @@ struct flash_info { > */ > #define SPI_NOR_OCTAL_DTR_READ BIT(19) /* Flash supports octal DTR Read. */ > #define SPI_NOR_OCTAL_DTR_PP BIT(20) /* Flash supports Octal DTR Page Program */ > +#define SPI_NOR_IO_MODE_EN_VOLATILE BIT(21) /* > + * Flash enables the best > + * available I/O mode via a > + * volatile bit. > + */ > > /* Part specific fixup hooks. */ > const struct spi_nor_fixups *fixups; >
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 34edfcf33172..c149b318e2e8 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -3089,6 +3089,9 @@ static int spi_nor_octal_dtr_enable(struct spi_nor *nor, bool enable) nor->write_proto == SNOR_PROTO_8_8_8_DTR)) return 0; + if (!(nor->flags & SNOR_F_IO_MODE_EN_VOLATILE)) + return 0; + ret = nor->params->octal_dtr_enable(nor, enable); if (ret) return ret; @@ -3474,6 +3477,9 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, if (info->flags & SPI_NOR_4B_OPCODES) nor->flags |= SNOR_F_4B_OPCODES; + if (info->flags & SPI_NOR_IO_MODE_EN_VOLATILE) + nor->flags |= SNOR_F_IO_MODE_EN_VOLATILE; + ret = spi_nor_set_addr_width(nor); if (ret) return ret; diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h index 10dc03506f93..c2755c82f978 100644 --- a/drivers/mtd/spi-nor/core.h +++ b/drivers/mtd/spi-nor/core.h @@ -27,6 +27,7 @@ enum spi_nor_option_flags { SNOR_F_HAS_4BIT_BP = BIT(12), SNOR_F_HAS_SR_BP3_BIT6 = BIT(13), SNOR_F_SOFT_RESET = BIT(14), + SNOR_F_IO_MODE_EN_VOLATILE = BIT(15), }; struct spi_nor_read_command { @@ -323,6 +324,11 @@ struct flash_info { */ #define SPI_NOR_OCTAL_DTR_READ BIT(19) /* Flash supports octal DTR Read. */ #define SPI_NOR_OCTAL_DTR_PP BIT(20) /* Flash supports Octal DTR Page Program */ +#define SPI_NOR_IO_MODE_EN_VOLATILE BIT(21) /* + * Flash enables the best + * available I/O mode via a + * volatile bit. + */ /* Part specific fixup hooks. */ const struct spi_nor_fixups *fixups;
We don't want to enter a stateful mode, where a X-X-X I/O mode is entered by setting a non-volatile bit, because in case of a reset or a crash, once in the non-volatile mode, we may not be able to recover in bootloaders and we may break the SPI NOR boot. Forbid by default the I/O modes that are set via a non-volatile bit. SPI_NOR_IO_MODE_EN_VOLATILE should be set just for the flashes that don't define the optional SFDP SCCR Map, so that we don't pollute the flash info flags. Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> --- drivers/mtd/spi-nor/core.c | 6 ++++++ drivers/mtd/spi-nor/core.h | 6 ++++++ 2 files changed, 12 insertions(+)