Re: [PATCH] Revert "mtd: spi-nor: Add a post BFPT fixup for MX25L25635E"

Andrew Jeffery andrew at aj.id.au
Wed Apr 17 15:48:01 AEST 2019


Ugh, that subject should have had "linux dev-5.0" in it, but y'know. I'll survive.

On Wed, 17 Apr 2019, at 15:16, Andrew Jeffery wrote:
> This reverts commit 2bffa65da43e399079dad5947c6aa9ab3cfa4ad4.
> 
> 5.0.x fails to boot on Witherspoon machines after an AC-cycle, with the
> following error:
> 
> > [    4.337766] ubi0: default fastmap pool size: 25
> > [    4.342321] ubi0: default fastmap WL pool size: 12
> > [    4.347232] ubi0: attaching mtd3
> > [    4.361487] ubi0: scanning is finished
> > [    4.365525] ubi0 error: ubi_read_volume_table: the layout volume was not found
> > [    4.372989] ubi0 error: ubi_attach_mtd_dev: failed to attach mtd3, error -22
> > [    4.380193] UBI error: cannot attach mtd3
> 
> Which leads to:
> 
> > [    4.553478] VFS: Cannot open root device "ubiblock0_1" or unknown-block(0,0): error -6
> > [    4.561550] Please append a correct "root=" boot option; here are the available partitions:
> > [    4.570029] 1f00           32768 mtdblock0
> > [    4.570038]  (driver?)
> > [    4.576671] 1f01             384 mtdblock1
> > [    4.576680]  (driver?)
> > [    4.583234] 1f02             128 mtdblock2
> > [    4.583240]  (driver?)
> > [    4.589883] 1f03           32256 mtdblock3
> > [    4.589892]  (driver?)
> > [    4.596520] 1f04           32768 mtdblock4
> > [    4.596529]  (driver?)
> > [    4.603080] 1f05             384 mtdblock5
> > [    4.603085]  (driver?)
> > [    4.609711] 1f06             128 mtdblock6
> > [    4.609719]  (driver?)
> > [    4.616338] 1f07           32256 mtdblock7
> > [    4.616347]  (driver?)
> > [    4.622901] 1f08          131072 mtdblock8
> > [    4.622907]  (driver?)
> > [    4.629539] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
> 
> A hint is provided earlier in the boot process:
> 
> > [    0.920597] aspeed-smc 1e620000.spi: Using 50 MHz SPI frequency
> > [    0.926753] aspeed-smc 1e620000.spi: mx25l25635e (32768 Kbytes)
> > [    0.932704] aspeed-smc 1e620000.spi: CE0 window [ 0x20000000 - 0x22000000 ] 32MB
> > [    0.940230] aspeed-smc 1e620000.spi: CE1 window [ 0x22000000 - 0x2a000000 ] 128MB
> > [    0.947812] aspeed-smc 1e620000.spi: read control register: 203c0641
> > [    1.435022] 3 fixed-partitions partitions found on MTD device bmc
> > [    1.441249] Creating 3 MTD partitions on "bmc":
> > [    1.445911] 0x000000000000-0x000000060000 : "u-boot"
> > [    1.455264] 0x000000060000-0x000000080000 : "u-boot-env"
> > [    1.465042] 0x000000080000-0x000002000000 : "obmc-ubi"
> > [    1.474914] aspeed-smc 1e620000.spi: Using 50 MHz SPI frequency
> > [    1.481102] aspeed-smc 1e620000.spi: mx25l25635e (32768 Kbytes)
> > [    1.487175] aspeed-smc 1e620000.spi: CE1 window [ 0x22000000 - 0x24000000 ] 32MB
> > [    1.494592] aspeed-smc 1e620000.spi: CE2 window [ 0x24000000 - 0x2c000000 ] 128MB
> > [    1.502173] aspeed-smc 1e620000.spi: read control register: 203c0041
> > [    1.705799] aspeed-smc 1e620000.spi: No good frequency, using dumb slow
> > [    1.717393] 3 fixed-partitions partitions found on MTD device alt-bmc
> > [    1.723851] Creating 3 MTD partitions on "alt-bmc":
> > [    1.728890] 0x000000000000-0x000000060000 : "alt-u-boot"
> > [    1.738950] 0x000000060000-0x000000080000 : "alt-u-boot-env"
> > [    1.748975] 0x000000080000-0x000002000000 : "alt-obmc-ubi"
> 
> Specifically, the control register state is exposed as:
> 
> > [    0.947812] aspeed-smc 1e620000.spi: read control register: 203c0641
> 
> The 0x3c opcode translates to DREAD4B for the mx25l25635f part, which is
> what is detected. The post BFPT fixup implemented in commit 2bffa65da43e
> ("mtd: spi-nor: Add a post BFPT fixup for MX25L25635E") detects the 'e'
> vs 'f' part based on the reported support for
> BFPT_DWORD5_FAST_READ_4_4_4, which implies 4B opcodes are supported
> (e.g. DREAD4B), however the aspeed-smc driver fails to put the
> controller into the right addressing mode to support sending DREAD4B, and
> so we reach a bad state.
> 
> In the interim, revert the upstream patch adding 'e' vs 'f' detection to
> avoid sending 4B opcodes.
> 
> The revert has been tested on a freshly flashed and power-cycled
> Witherspoon, both with and without the patch applied, confirming the
> broken behaviour in the former case and a successful boot in the latter.
> 
> Cc: Andrew Geissler <geissonator at gmail.com>
> Reported-by: George Keishing <gkeishin at in.ibm.com>
> Investigated-by: Cédric Le Goater <clg at kaod.org>
> Investigated-by: Eddie James <eajames at linux.ibm.com>
> Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
> ---
>  drivers/mtd/spi-nor/spi-nor.c | 29 +----------------------------
>  1 file changed, 1 insertion(+), 28 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 5a5a47651bf9..9f85ab5fc569 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -1681,31 +1681,6 @@ static int sr2_bit7_quad_enable(struct spi_nor *nor)
>  		.addr_width = 3,					\
>  		.flags = SPI_NOR_NO_FR | SPI_S3AN,
>  
> -static int
> -mx25l25635_post_bfpt_fixups(struct spi_nor *nor,
> -			    const struct sfdp_parameter_header *bfpt_header,
> -			    const struct sfdp_bfpt *bfpt,
> -			    struct spi_nor_flash_parameter *params)
> -{
> -	/*
> -	 * MX25L25635F supports 4B opcodes but MX25L25635E does not.
> -	 * Unfortunately, Macronix has re-used the same JEDEC ID for both
> -	 * variants which prevents us from defining a new entry in the parts
> -	 * table.
> -	 * We need a way to differentiate MX25L25635E and MX25L25635F, and it
> -	 * seems that the F version advertises support for Fast Read 4-4-4 in
> -	 * its BFPT table.
> -	 */
> -	if (bfpt->dwords[BFPT_DWORD(5)] & BFPT_DWORD5_FAST_READ_4_4_4)
> -		nor->flags |= SNOR_F_4B_OPCODES;
> -
> -	return 0;
> -}
> -
> -static struct spi_nor_fixups mx25l25635_fixups = {
> -	.post_bfpt = mx25l25635_post_bfpt_fixups,
> -};
> -
>  /* NOTE: double check command sets and memory organization when you add
>   * more nor chips.  This current list focusses on newer chips, which
>   * have been converging on command sets which including JEDEC ID.
> @@ -1843,9 +1818,7 @@ static const struct flash_info spi_nor_ids[] = {
>  	{ "mx25l12855e", INFO(0xc22618, 0, 64 * 1024, 256, 0) },
>  	{ "mx25u12835f", INFO(0xc22538, 0, 64 * 1024, 256,
>  			 SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> -	{ "mx25l25635e", INFO(0xc22019, 0, 64 * 1024, 512,
> -			 SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)
> -			 .fixups = &mx25l25635_fixups },
> +	{ "mx25l25635e", INFO(0xc22019, 0, 64 * 1024, 512, SPI_NOR_DUAL_READ 
> | SPI_NOR_QUAD_READ) },
>  	{ "mx25u25635f", INFO(0xc22539, 0, 64 * 1024, 512, SECT_4K | 
> SPI_NOR_4B_OPCODES) },
>  	{ "mx25l25655e", INFO(0xc22619, 0, 64 * 1024, 512, 0) },
>  	{ "mx66l51235f", INFO(0xc2201a, 0, 64 * 1024, 1024, SPI_NOR_DUAL_READ 
> | SPI_NOR_QUAD_READ) },
> -- 
> 2.19.1
> 
>


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