Hi Tudor, On Thu, May 9, 2019 at 8:56 AM <Tudor.Ambarus@xxxxxxxxxxxxx> wrote: > When the configuration register QUAD bit CR[1] is 1, only the WRR command format > with 16 data bits may be used, WRR with 8 bits is not recognized and hence the > FFs. You probably set quad bit in u-boot, while others don't. We can verify this > assumption with the patch form below. Can you try it? Thanks! > --- a/drivers/mtd/spi-nor/spi-nor.c > +++ b/drivers/mtd/spi-nor/spi-nor.c > +static int spi_nor_clear_block_protection(struct spi_nor *nor) > +{ > + int ret; > + u8 sr, cr, sr_cr[2] = {0}; > + u8 mask = SR_BP2 | SR_BP1 | SR_BP0; > + > + ret = read_cr(nor); > + dev_dbg(nor->dev, "CR = %08x\n", ret); > + if (ret < 0) { > + dev_err(nor->dev, "error while reading CR\n"); > + return ret; > + } > + cr = ret; > + > + if (cr & CR_QUAD_EN_SPAN) { > + /* disable quad if already set, must do it with 16-bit WRR */ > + ret = write_sr_cr(nor, sr_cr); > + if (ret) { > + dev_err(nor->dev, "error diasbling quad mode\n"); disabling > + return ret; > + } renesas_spi e6b10000.spi: DMA available renesas_spi e6b10000.spi: registered master spi0 spi spi0.0: setup mode 3, 8 bits/w, 30000000 Hz max --> 0 m25p80 spi0.0: bfpt.dwords[1] = ffffffff m25p80 spi0.0: bfpt.dwords[2] = ffffffff m25p80 spi0.0: bfpt.dwords[3] = ffffffff m25p80 spi0.0: bfpt.dwords[4] = ffffffff m25p80 spi0.0: bfpt.dwords[5] = ffffffff m25p80 spi0.0: bfpt.dwords[6] = ffffffff m25p80 spi0.0: bfpt.dwords[7] = ffffffff m25p80 spi0.0: bfpt.dwords[8] = ffffffff m25p80 spi0.0: bfpt.dwords[9] = ffffffff m25p80 spi0.0: bfpt.dwords[10] = 00000000 m25p80 spi0.0: bfpt.dwords[11] = 00000000 m25p80 spi0.0: bfpt.dwords[12] = 00000000 m25p80 spi0.0: bfpt.dwords[13] = 00000000 m25p80 spi0.0: bfpt.dwords[14] = 00000000 m25p80 spi0.0: bfpt.dwords[15] = 00000000 m25p80 spi0.0: bfpt.dwords[16] = 00000000 m25p80 spi0.0: failed to parse BFPT: err = -22 m25p80 spi0.0: spi_nor_init_params sfdp parse failed, ret =-22 m25p80 spi0.0: SR and CR before quad_enable: m25p80 spi0.0: SR = 00000000 m25p80 spi0.0: CR = 00000002 m25p80 spi0.0: SR and CR after quad_enable: m25p80 spi0.0: SR = 00000000 m25p80 spi0.0: CR = 00000002 m25p80 spi0.0: s25fl512s (65536 Kbytes) m25p80 spi0.0: mtd .name = spi0.0, .size = 0x4000000 (64MiB), .erasesize = 0x00040000 (256KiB) .numeraseregions = 0 3 fixed-partitions partitions found on MTD device spi0.0 Creating 3 MTD partitions on "spi0.0": 0x000000000000-0x000000080000 : "loader" 0x000000080000-0x000000600000 : "user" 0x000000600000-0x000004000000 : "flash" renesas_spi e6b10000.spi: registered child spi0.0 renesas_spi e6b10000.spi: probed And /dev/mtd0 reading works fine. Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds