RE: [PATCH v3 1/2] mtd: spi-nor: add support to non-uniform SFDP SPI NOR flash memories

[Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx>]

Hi,

> -----Original Message-----
> From: Boris Brezillon [mailto:boris.brezillon@xxxxxxxxxxx]
> Sent: Monday, October 22, 2018 3:57 PM
> To: Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx>
> Cc: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>; richard@xxxxxx; Mark
> Brown <broonie@xxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx;
> nicolas.ferre@xxxxxxxxxxxxx; marek.vasut@xxxxxxxxx;
> cyrille.pitchen@xxxxxxxxxxxxx; linux-mtd@xxxxxxxxxxxxxxxxxxx;
> Cristian.Birsan@xxxxxxxxxxxxx; Cyrille Pitchen <cyrille.pitchen@xxxxxxxxxx>;
> computersforpeace@xxxxxxxxx; dwmw2@xxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH v3 1/2] mtd: spi-nor: add support to non-uniform SFDP SPI
> NOR flash memories
> 
> On Mon, 22 Oct 2018 10:03:55 +0000
> Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx> wrote:
> 
> > --- a/drivers/mtd/spi-nor/spi-nor.c
> > +++ b/drivers/mtd/spi-nor/spi-nor.c
> > @@ -2863,26 +2863,36 @@ static u8 spi_nor_smpt_read_dummy(const struct
> spi_nor *nor, const u32 settings)
> >   * @nor:       pointer to a 'struct spi_nor'
> >   * @smpt:      pointer to the sector map parameter table
> >   */
> > -static const u32 *spi_nor_get_map_in_use(struct spi_nor *nor, const
> > u32 *smpt)
> > +static const u32 *spi_nor_get_map_in_use(struct spi_nor *nor, const
> > +u32 *smpt, u32 smpt_len)
> >  {
> >         const u32 *ret = NULL;
> > -       u32 i, addr;
> > +       u32 i, addr, nmaps;
> >         int err;
> >         u8 addr_width, read_opcode, read_dummy;
> >         u8 read_data_mask, data_byte, map_id;
> > +       bool map_id_is_valid = false;
> >
> >         addr_width = nor->addr_width;
> >         read_dummy = nor->read_dummy;
> >         read_opcode = nor->read_opcode;
> >
> > +       pr_info("Start [addr_width:%08x, read_dumy:%0x8,
> > + read_opcode:%08x]\n", nor->addr_width, nor->read_dummy,
> > + nor->read_opcode);
> > +
> > +       for (i = 0; i<smpt_len; i++)
> > +               pr_info("%s:%i smpt[%d]=%08x\n", __func__, __LINE__,
> > + i, smpt[i]);
> > +
> >         map_id = 0;
> > -       i = 0;
> >         /* Determine if there are any optional Detection Command Descriptors */
> > -       while (!(smpt[i] & SMPT_DESC_TYPE_MAP)) {
> > +       for (i = 0; i< smpt_len; i++) {
> 
> 				   ^ i += 2) {
> 
> > +               if ((smpt[i] & SMPT_DESC_TYPE_MAP))
> > +                       break;
> > +
> >                 read_data_mask = SMPT_CMD_READ_DATA(smpt[i]);
> >                 nor->addr_width = spi_nor_smpt_addr_width(nor, smpt[i]);
> >                 nor->read_dummy = spi_nor_smpt_read_dummy(nor, smpt[i]);
> >                 nor->read_opcode = SMPT_CMD_OPCODE(smpt[i]);
> > +               pr_info("smpt[%d]=[addr_width:%08x, read_dumy:%0x8,
> > + read_opcode:%08x]\n", i, nor->addr_width, nor->read_dummy,
> > + nor->read_opcode);
> > +
> >                 addr = smpt[i + 1];
> >
> >                 err = spi_nor_read_raw(nor, addr, 1, &data_byte); @@
> > -2894,18 +2904,36 @@ static const u32 *spi_nor_get_map_in_use(struct
> spi_nor *nor, const u32 *smpt)
> >                  * Configuration that is currently in use.
> >                  */
> >                 map_id = map_id << 1 | !!(data_byte & read_data_mask);
> > +               map_id_is_valid = true;
> >                 i = i + 2;
> 
> Drop the above line (i = i + 2).
> 

[    1.632190] Start [addr_width:00000000, read_dumy:08, read_opcode:00000000]                                                   
[    1.639148] spi_nor_get_map_in_use:2882 smpt[0]=08ff65fc                                                                      
[    1.644451] spi_nor_get_map_in_use:2882 smpt[1]=00000004                                                                      
[    1.649755] spi_nor_get_map_in_use:2882 smpt[2]=04ff65fc                                                                      
[    1.655057] spi_nor_get_map_in_use:2882 smpt[3]=00000002                                                                      
[    1.660360] spi_nor_get_map_in_use:2882 smpt[4]=02ff65fd                                                                      
[    1.665662] spi_nor_get_map_in_use:2882 smpt[5]=00000004                                                                      
[    1.670965] spi_nor_get_map_in_use:2882 smpt[6]=ff0201fe                                                                      
[    1.676267] spi_nor_get_map_in_use:2882 smpt[7]=00007ff1                                                                      
[    1.681571] spi_nor_get_map_in_use:2882 smpt[8]=00037ff4                                                                      
[    1.686874] spi_nor_get_map_in_use:2882 smpt[9]=03fbfff4                                                                      
[    1.692176] spi_nor_get_map_in_use:2882 smpt[10]=ff0203fe                                                                     
[    1.697566] spi_nor_get_map_in_use:2882 smpt[11]=03fbfff4                                                                     
[    1.702954] spi_nor_get_map_in_use:2882 smpt[12]=00037ff4                                                                     
[    1.708343] spi_nor_get_map_in_use:2882 smpt[13]=00007ff1                                                                     
[    1.713732] spi_nor_get_map_in_use:2882 smpt[14]=ff0005ff                                                                     
[    1.719120] spi_nor_get_map_in_use:2882 smpt[15]=03fffff4                                                                     
[    1.724509] smpt[0]=[addr_width:00000000, read_dumy:08, read_opcode:00000065]                                                 
[    1.731650] smpt[1]=[addr_width:00000000, read_dumy:08, read_opcode:00000000]                                                 
[    1.738791] smpt[2]=[addr_width:00000000, read_dumy:08, read_opcode:00000065]                                                 
[    1.745932] spi_nor_get_map_in_use:2911 map_id=0 smpt_len:16 i=:3                                                             
[    1.752018] End [addr_width:00000000, read_dumy:08, read_opcode:00000065]         

Also, one more thing when we are returning from the function, we are over-writing the values of addr_widthm read_dummy and read_opcode.
Is this correct?

out:
        nor->addr_width = addr_width;
        nor->read_dummy = read_dummy;
        nor->read_opcode = read_opcode;
        return ret;
}

--
Regards
Yogesh Gaur
> >         }
> >
> > -       /* Find the matching configuration map */
> > -       while (SMPT_MAP_ID(smpt[i]) != map_id) {
> > -               if (smpt[i] & SMPT_DESC_END)
> > -                       goto out;
> > +       if (map_id_is_valid)
> > +               pr_info("%s:%i map_id=%d\n", __func__, __LINE__, map_id);
> > +       else
> > +               pr_info("%s:%i NO map_id\n", __func__, __LINE__);
> > +
> > +       for (nmaps = 0; i< smpt_len; nmaps++) {
> > +               if((smpt[i] & SMPT_DESC_TYPE_MAP))
> > +                       continue;
> > +
> > +               if(!map_id_is_valid) {
> > +                       if (nmaps) {
> > +                               ret = NULL;
> > +                               break;
> > +                       }
> > +
> > +                       ret = smpt+i;
> > +               } else if (map_id == SMPT_MAP_ID(smpt[i])) {
> > +                       ret = smpt+i;
> > +                       break;
> > +               }
> > +
> >                 /* increment the table index to the next map */
> >                 i += SMPT_MAP_REGION_COUNT(smpt[i]) + 1;
> >         }
> >
> > -       ret = smpt + i;
> > +       pr_info("End [addr_width:%08x, read_dumy:%0x8,
> > + read_opcode:%08x]\n", nor->addr_width, nor->read_dummy,
> > + nor->read_opcode);
> >         /* fall through */
> >  out:
> >         nor->addr_width = addr_width;


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