Hi Bin,
On 22 April 2015 at 12:44, Bin Meng bmeng.cn@gmail.com wrote:
Hi Jagan,
On Wed, Apr 22, 2015 at 3:03 PM, Jagan Teki jagannadh.teki@gmail.com wrote:
Hi Bin,
On 22 April 2015 at 12:14, Bin Meng bmeng.cn@gmail.com wrote:
Hi Jagan,
On Tue, Apr 21, 2015 at 8:47 PM, Jagan Teki jagannadh.teki@gmail.com wrote:
Hi Bin,
On 20 April 2015 at 15:02, Bin Meng bmeng.cn@gmail.com wrote:
Hi Jagan,
On Fri, Apr 17, 2015 at 4:48 PM, Jagan Teki jagannadh.teki@gmail.com wrote:
Hi Bin,
On 17 April 2015 at 07:14, Bin Meng bmeng.cn@gmail.com wrote: > Hi Jagan, > > On Fri, Apr 17, 2015 at 2:09 AM, Jagan Teki jagannadh.teki@gmail.com wrote: >> Hi Bin, >> >> I think you have a different interpretation of sector size here- >> >> /* The size listed here is what works with SPINOR_OP_SE, which isn't >> * necessarily called a "sector" by the vendor. >> */ >> Say for example SST25VF040B has 8 sectors of which each sector size is >> 64 * 1024 out of this we can use 4K sector erase or 32K sector erase or >> 64K sector erase through flags. >> >> Linux does follow the same- >> /* SST -- large erase sizes are "overlays", "sectors" are 4K */ >> { "sst25vf040b", INFO(0xbf258d, 0, 64 * 1024, 8, SECT_4K | >> SST_WRITE) }, >> { "sst25vf080b", INFO(0xbf258e, 0, 64 * 1024, 16, SECT_4K | >> SST_WRITE) }, >> { "sst25vf016b", INFO(0xbf2541, 0, 64 * 1024, 32, SECT_4K | >> SST_WRITE) }, >> { "sst25vf032b", INFO(0xbf254a, 0, 64 * 1024, 64, SECT_4K | >> SST_WRITE) }, >> >> Please check it. > > > Yes, I know this pretty well. And I want to change this behavior, as > my cover letter says. > > Currently the 'sf erase' command operates on a 64KB granularity, while > the actual erase command is 4KB granularity, which is inconsistent and > causes confusion.
It never related to 'sf erase' instead based on the 'params->flags' sf_probe will decide which erase_cmd with erase_size will use.
No, it is related. See cmd_sf.c:
I'm not getting your point- how could it erase use 64K sector size instead of 4K.
It indeed erases 64K sector size. You need check the logic in spi_flash_validate_params().
We're assigning erase_size to sector_size only when SECT_4K and SECT_32K and for these erase_size becomes direct values, please check this.
You previous email already said: the 'sf erase' command depends on *flash->sector_size*
/* Compute erase sector and command */ if (params->flags & SECT_4K) { flash->erase_cmd = CMD_ERASE_4K; flash->erase_size = 4096; } else if (params->flags & SECT_32K) { flash->erase_cmd = CMD_ERASE_32K; flash->erase_size = 32768; } else { flash->erase_cmd = CMD_ERASE_64K; flash->erase_size = flash->sector_size; }Here the codes says: *flash->erase_size*
So when I give a 'sf erase 0 100' it erase 64KB even if you have SECT_4K.
Example: "SST25WF080", 0xbf2505, 0x0, 64 * 1024, 16, RD_NORM, SECT_4K | SST_WR},
sf probe gives sector_size = 64 * 1024 and erase_size = 4096
sf erase 0 100 sf_parse_len_arg len returns 100 and spi_flash_cmd_erase_ops returns "SF: Erase offset/length not multiple of erase size"
Example: "SST25WF080", 0xbf2505, 0x0, 64 * 1024, 16, RD_NORM, SST_WR},
sf probe gives sector_size = 64 * 1024 and erase_size = 64 * 1024
sf erase 0 100 sf_parse_len_arg len returns 100 and spi_flash_cmd_erase_ops returns "SF: Erase offset/length not multiple of erase size"
Still have any concerns, please come to IRC for more discussion
Suppose the sector size is 4K
flash->sector_size = 0x1000
- erase 4K len flash (it's total erase length)
# sf erase 0x0 0x1000
len_arg = simple_strtoul(arg, &ep, 16); gives - 0x1000
*len becomes 0x1000
- erase 4K+1 len flash
# sf erase 0x0 +0x1001
len_arg = simple_strtoul(arg, &ep, 16); gives - 0x1001
*len becomes 0x2000
All the way when it goes to sf_ops.c erase will take by means of erase_size which is assigned in sf_probe.c based on flags like 4K 32K or 64K.
thanks!