Hi, 

-----Original Message-----
From: Boris Brezillon [mailto:boris.brezillon at bootlin.com]
Sent: Tuesday, October 23, 2018 2:18 PM
To: Yogesh Narayan Gaur <redacted>
Cc: Cristian.Birsan at microchip.com; Tudor Ambarus
[off-list ref]; richard at nod.at; Mark Brown
[off-list ref]; linux-kernel at vger.kernel.org;
nicolas.ferre at microchip.com; marek.vasut at gmail.com;
cyrille.pitchen at microchip.com; linux-mtd at lists.infradead.org; Cyrille Pitchen
[off-list ref]; computersforpeace at gmail.com;
dwmw2 at infradead.org; linux-arm-kernel at lists.infradead.org
Subject: Re: [PATCH v3 1/2] mtd: spi-nor: add support to non-uniform SFDP SPI
NOR flash memories

On Tue, 23 Oct 2018 08:18:35 +0000
Yogesh Narayan Gaur [off-list ref] wrote:

quoted

I have added the prints in m25p80_read() and in flexspi controller prepare_lut

and read_rxfifo() func.

quoted

In these have added prints for data variable of struct op and data which being

read by the controller from the flash.

quoted

[    2.091467] smpt[0]=[addr_width:00000003, read_dumy:00000008,

read_opcode:00000065, data_mask:00000008]

quoted

[    2.099113] m25p80_read, nor[op:00000065 addr_width:00000003,

dummy:00000008, len:00000001

quoted

[    2.107367] m25p80_read, cmd[opcode:65 bwidth:1] aadr[val:4, nbytes:3,

bwidth:1]

quoted

[    2.114753] m25p80_read, dummy[nbytes:1 bwidth:1] data[bwidth:1,

nbytes:1]

quoted

[    2.121706] nxp_fspi_prepare_lut cmd[opcode:65 bwidth:1] aadr[val:4,

nbytes:3, bwidth:1]

quoted

[    2.129786] dummy[nbytes:1 bwidth:1] data[dir:0 bwidth:1, nbytes:1]
[    2.136132] nxp-fspi 20c0000.flexspi: CMD[65] lutval[0:8180465

1:24003008      2:0     3:0]

quoted

[    2.144223] nxp_fspi_read_rxfifo, ReadData op.buf[0x00]
[    2.151004] smpt_read[1] addr[00000004], data_byte[00000000]

err:00000000

quoted

[    2.157782] smpt[2]=[addr_width:00000003, read_dumy:00000008,

read_opcode:00000065, data_mask:00000004]

quoted

[    2.165429] m25p80_read, nor[op:00000065 addr_width:00000003,

dummy:00000008, len:00000001

quoted

[    2.173683] m25p80_read, cmd[opcode:65 bwidth:1] aadr[val:2, nbytes:3,

bwidth:1]

quoted

[    2.181068] m25p80_read, dummy[nbytes:1 bwidth:1] data[bwidth:1,

nbytes:1]

quoted

[    2.188021] nxp_fspi_prepare_lut cmd[opcode:65 bwidth:1] aadr[val:2,

nbytes:3, bwidth:1]

quoted

[    2.196101] dummy[nbytes:1 bwidth:1] data[dir:0 bwidth:1, nbytes:1]
[    2.202447] nxp-fspi 20c0000.flexspi: CMD[65] lutval[0:8180465

1:24003008      2:0     3:0]

quoted

[    2.210539] nxp_fspi_read_rxfifo, ReadData op.buf[0x02]
[    2.217319] smpt_read[3] addr[00000002], data_byte[00000002]

err:00000000

quoted

[    2.224098] smpt[4]=[addr_width:00000003, read_dumy:00000008,

read_opcode:00000065, data_mask:00000002]

quoted

[    2.231744] m25p80_read, nor[op:00000065 addr_width:00000003,

dummy:00000008, len:00000001

quoted

[    2.239998] m25p80_read, cmd[opcode:65 bwidth:1] aadr[val:4, nbytes:3,

bwidth:1]

quoted

[    2.247383] m25p80_read, dummy[nbytes:1 bwidth:1] data[bwidth:1,

nbytes:1]

quoted

[    2.254336] nxp_fspi_prepare_lut cmd[opcode:65 bwidth:1] aadr[val:4,

nbytes:3, bwidth:1]

quoted

[    2.262416] dummy[nbytes:1 bwidth:1] data[dir:0 bwidth:1, nbytes:1]
[    2.268762] nxp-fspi 20c0000.flexspi: CMD[65] lutval[0:8180465

1:24003008      2:0     3:0]

quoted

[    2.276854] nxp_fspi_read_rxfifo, ReadData op.buf[0x00]
[    2.283634] smpt_read[5] addr[00000004], data_byte[00000000]

err:00000000

quoted

[    2.290412] spi_nor_get_map_in_use:2915 map_id=0 smpt_len:16 i=:6
[    2.296496] End [addr_width:00000003, read_dumy:00000008,

read_opcode:00000065] ReturnVal:00000000

quoted

[    2.305444] spi_nor_parse_smpt:3065
[    2.308924] m25p80 spi0.0: failed to parse SMPT (err = -22)

quoted

Next thing you can do is read the CR2NV reg (using the RDAR command)
and check the RL (Read Latency) and AL (Address Length) values.

Please let me know how to read CR2NV register.

Actually, RDAR is already what you use to read the map_id, and we need to use
it to read the register that contains the number of dummy cycles and the number
of address bytes to use for RDAR operations. Looks like we have a chicken and
egg situation here :-).

Let's try something else:

1/ create an u8 array of 16 entries named data_bytes

for each loop iteration (the first for loop):
2/ set ->addr_width to 3 and ->read_dummy to 0 3/ call spi_nor_read_raw(nor,
addr, ARRAY_SIZE(data_bytes), data_bytes) 4/ dump the data_bytes buf 5/ set -

quoted

addr_width to 4 6/ call spi_nor_read_raw(nor, addr, ARRAY_SIZE(data_bytes),

data_bytes) 7/ dump the data_bytes buf

If the SPI driver is working correctly, we should be able to figure out the right
value for ->addr_width and ->read_dummy.

Ok, I would try with the suggested change.
But till the point we not able to figure out actual failure reason can we have below changes pushed-in

@@ -3139,6 +3177,17 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor,
                switch (SFDP_PARAM_HEADER_ID(param_header)) {
                case SFDP_SECTOR_MAP_ID:
                        err = spi_nor_parse_smpt(nor, param_header);
+                       if (err) {
+                               dev_warn(dev,
+                               "failed to parse SMPT (err = %d)\n",
+                               err);
+                               /*
+                                * SMPT parsing is optional, let's not drop
+                                * all information we extracted so far just
+                                * because it failed.
+                                */
+                               err = 0;
+                       }

--

Regards
Yogesh Gaur.
 

Thanks,

Boris