Commit graph

2,087 commits

Author SHA1 Message Date
Huang Shijie
3f97c6ff6d mtd: nand: add SanDisk manufacturer ID
Add the manufactor ID for SanDisk.
Make preparation for SanDisk SDTNRGAMA-008G.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-20 11:23:28 -08:00
Huang Shijie
94d04e824f mtd: nand: add support for Samsung K9LCG08U0B
Assume that:
          tmp = ((extid >> 2) & 0x04) | (extid & 0x03));

From the K9LCG08U0B's datasheet, we know that:
  the oob size is 640 when tmp is 6;
  the oob size is 1024 when tmp is 7;

Signed-off-by: Huang Shijie <b32955@freescale.com>
[Brian: fixed compile issue]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-20 11:23:28 -08:00
Rodolfo Giometti
3db227b648 mtd: nand: pxa3xx: Add support for 2048 bytes page size devices
This commit adds support for devices with 2048B page sizes and
4-bit ECC strength requirements. This is achieved by enabling the BCH
ECC engine, which provides a higher strength: 16-bit over 2048 bytes.

Additionally, add a proper ECC layout to model the controller's view
of the device (where 'U' means unused and 'B' is the bad block marker):

 ----------------------------------------------------
 | 2048B data | B | B | 30B spare | 30B ECC | U | U |
 ----------------------------------------------------

Signed-off-by: Rodolfo Giometti <giometti@linux.it>
[Brian: updated with Ezequiel's patch description]
Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-20 11:20:47 -08:00
Uwe Kleine-König
05f7835975 mtd: nand: don't use {read,write}_buf for 8-bit transfers
According to the Open NAND Flash Interface Specification (ONFI) Revision
3.1 "Parameters are always transferred on the lower 8-bits of the data
bus." for the Get Features and Set Features commands.

So using read_buf and write_buf is wrong for 16-bit wide nand chips as
they use I/O[15:0]. The Get Features command is easily fixed using 4
times the read_byte callback. For Set Features implement a new
overwritable callback "write_byte". Still I expect the default to work
just fine for all controllers and making it overwriteable was just done
for symmetry.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[Brian: fixed warning]
Tested-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-14 17:22:37 -08:00
Brian Norris
8429bb3975 mtd: nand: support Micron READ RETRY
Micron provides READ RETRY support via the ONFI vendor-specific
parameter block (to indicate how many read-retry modes are available)
and the ONFI {GET,SET}_FEATURES commands with a vendor-specific feature
address (to support reading/switching the current read-retry mode).

The recommended sequence is as follows:

  1. Perform PAGE_READ operation
  2. If no ECC error, we are done
  3. Run SET_FEATURES with feature address 89h, mode 1
  4. Retry PAGE_READ operation
  5. If ECC error and there are remaining supported modes, increment the
     mode and return to step 3. Otherwise, this is a true ECC error.
  6. Run SET_FEATURES with feature address 89h, mode 0, to return to the
     default state.

This patch implements the chip->setup_read_retry() callback for
Micron and fills in the chip->read_retries.

Tested on Micron MT29F32G08CBADA, which supports 8 read-retry modes.

The Micron vendor-specific table was checked against the datasheets for
the following Micron NAND:

Needs retry   Cell-type    Part number          Vendor revision    Byte 180
-----------   ---------    ----------------     ---------------    ------------
No            SLC          MT29F16G08ABABA      1                  Reserved (0)
No            MLC          MT29F32G08CBABA      1                  Reserved (0)
No            SLC          MT29F1G08AACWP       1                  0
Yes           MLC          MT29F32G08CBADA      1                  08h
Yes           MLC          MT29F64G08CBABA      2                  08h

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>
2014-01-13 23:13:05 -08:00
Brian Norris
ba84fb5952 mtd: nand: add generic READ RETRY support
Modern MLC (and even SLC?) NAND can experience a large number of
bitflips (beyond the recommended correctability capacity) due to drifts
in the voltage threshold (Vt). These bitflips can cause ECC errors to
occur well within the expected lifetime of the flash. To account for
this, some manufacturers provide a mechanism for shifting the Vt
threshold after a corrupted read.

The generic pattern seems to be that a particular flash has N read retry
modes (where N = 0, traditionally), and after an ECC failure, the host
should reconfigure the flash to use the next available mode, then retry
the read operation. This process repeats until all bitfips can be
corrected or until the host has tried all available retry modes.

This patch adds the infrastructure support for a
vendor-specific/flash-specific callback, used for setting the read-retry
mode (i.e., voltage threshold).

For now, this patch always returns the flash to mode 0 (the default
mode) after a successful read-retry, according to the flowchart found in
Micron's datasheets. This may need to change in the future if it is
determined that eventually, mode 0 is insufficient for the majority of
the flash cells (and so for performance reasons, we should leave the
flash in mode 1, 2, etc.).

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>
2014-01-13 23:12:58 -08:00
Brian Norris
b72f3dfb8c mtd: nand: localize ECC failures per page
ECC failures can be tracked at the page level, not the do_read_ops level
(i.e., a potentially multi-page transaction).

This helps prepare for READ RETRY support.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>
2014-01-13 23:12:38 -08:00
Ezequiel Garcia
1963ff97ca mtd: nand: pxa3xx: Add "armada370-nand" compatible
Now that the driver can support the Armada 370/XP SoC NAND controller,
add the devicetree compatible string, enabling its use.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-12 23:47:36 -08:00
Gerhard Sittig
10de271f93 mtd: mpc5121_nfc: adjust for OF based clock lookup
after device tree based clock lookup became available, the NAND
flash driver need no longer use the previous global "nfc_clk" name,
but should use the "ipg" clock name specific to the OF node

Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Gerhard Sittig <gsi@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
2014-01-12 18:53:05 +01:00
Huang Shijie
e07caa3687 mtd: denali: kill the NAND_MAX_PAGESIZE/NAND_MAX_OOBSIZE
This patch kills the NAND_MAX_PAGESIZE/NAND_MAX_OOBSIZE by the following
way:
 1.) change the @buf field of nand_buf{} from an array to a pointer.
     also remove the DENALI_BUF_SIZE macro.

 2.) Before we call the nand_scan_ident, we allocate a temporary buffer
     whose size is PAGE_SIZE.

 3.) After we finish the nand_scan_ident, we have already getten the
     page size and oob size. We will allocate the right buffer size
     again.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-11 12:20:15 -08:00
Huang Shijie
a5900554a8 mtd: mxc-nand: kill the NAND_MAX_PAGESIZE/NAND_MAX_OOBSIZE
We kill the NAND_MAX_PAGESIZE/NAND_MAX_OOBSIZE by the following way:
 1.) Before we call the nand_scan_ident, we allocate a temporary buffer
     whose size is PAGE_SIZE.
 2.) After we finish the nand_scan_ident, we have already getten the
     page size and oob size. We will allocate the right buffer size
     again.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-11 12:20:06 -08:00
Prabhakar Kushwaha
2fec386a94 mtd: nand: Update mtd.name assignment type to u64 for IFC, eLBC
mtd.name is assigned to IFC NAND physical address. Assignment type is u32.
It is not providing correct physical address of IFC NAND.

Update assignment type to u64.

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-11 12:07:35 -08:00
Cai Zhiyong
092b6a1dd0 mtd: nand: assign mtd->name in find_full_id_nand
This patch assigned the type->name to mtd->name when mtd->name is
NULL in function "find_full_id_nand".
mtd->name is NULL may cause some problem.

Signed-off-by: Cai Zhiyong <caizhiyong@huawei.com>
Acked-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-11 12:07:18 -08:00
Josh Triplett
88c305912d mtd: denali: Drop print of build date/time
The kernel already has this information, and individual drivers
shouldn't duplicate that.  This also eliminates the use of __DATE__ and
__TIME__, which make the build non-deterministic.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-09 08:52:48 -08:00
Brian Norris
cf0e4d2b3f mtd: omap2: use nand_base defaults for polled I/O
The omap_{read,write}_buf{8,16}() functions are identical to the default
nand_base versions. Just let nand_base assign them in the
NAND_OMAP_POLLED case.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Tested-by: Pekon Gupta <pekon@ti.com>
2014-01-07 10:07:35 -08:00
Brian Norris
103cdd8520 mtd: nand-gpio: don't waste memory for OF failure
We shouldn't try to allocate a resource until we're sure the
of_property_read_u64() call didn't fail. This is especially important if
we use this code for both CONFIG_OF and !CONFIG_OF builds, since
of_property_read_u64() will always return -ENOSYS for !CONFIG_OF.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:07:34 -08:00
Jingoo Han
a01eb2043b mtd: plat_nand: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:07:33 -08:00
Jingoo Han
ffdac7cd31 mtd: plat_nand: Use devm_*() functions
Use devm_*() functions to make cleanup paths simpler.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:07:33 -08:00
Jingoo Han
bb13bec74e mtd: sharpsl: use dev_err() instead of printk()
Use dev_err() instead of printk() to provide a better message
to userspace.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:07:31 -08:00
Jingoo Han
4867d582d5 mtd: orion_nand: use dev_err() instead of printk()
Use dev_err() instead of printk() to provide a better message
to userspace.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:07:31 -08:00
Jingoo Han
67b19a631e mtd: fsmc_nand: use dev_warn() instead of printk()
Use dev_warn() instead of printk() to provide a better message
to userspace.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:07:03 -08:00
Jingoo Han
1295f97002 mtd: atmel_nand: use dev_err() instead of printk()
Use dev_err() instead of printk() to provide a better message
to userspace.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:07:03 -08:00
Jingoo Han
b5d306c034 mtd: sh_flctl: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:07:02 -08:00
Jingoo Han
ad74581007 mtd: s3c2410: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:07:01 -08:00
Jingoo Han
61a623fe0d mtd: mpc5121_nfc: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:07:01 -08:00
Jingoo Han
8ecb66ba39 mtd: lpc32xx_slc: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:07:00 -08:00
Jingoo Han
3479c9dcef mtd: lpc32xx_mlc: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:06:58 -08:00
Jingoo Han
24e9971d3d mtd: nand-gpio: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:06:57 -08:00
Jingoo Han
d9a21ae8e5 mtd: fsmc_nand: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-07 10:06:46 -08:00
Jingoo Han
006692319b mtd: davinci_nand: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:30 -08:00
Jingoo Han
844a72c5af mtd: txx9ndfmc: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:30 -08:00
Jingoo Han
51b37b8a72 mtd: jz4740_nand: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:30 -08:00
Jingoo Han
95cdd5a48a mtd: fsl_ifc_nand: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:30 -08:00
Jingoo Han
3fc697cadf mtd: fsl_elbc_nand: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:30 -08:00
Jingoo Han
bf521a3b80 mtd: diskonchip: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:30 -08:00
Jingoo Han
1f4bd45a7e mtd: cs553x_nand: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:29 -08:00
Jingoo Han
4caab3ba59 mtd: cmx270_nand: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:29 -08:00
Jingoo Han
9fd9e4cd1a mtd: cafe_nand: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:29 -08:00
Jingoo Han
aad0753183 mtd: bf5xx_nand: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:29 -08:00
Jingoo Han
ce3737f047 mtd: au1550nd: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:29 -08:00
Jingoo Han
fc59a51e48 mtd: sharpsl: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:28 -08:00
Jingoo Han
36cbcf85eb mtd: orion_nand: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:28 -08:00
Jingoo Han
9e3677a813 mtd: atmel_nand: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:28 -08:00
Jingoo Han
8f91fb681e mtd: tmio_nand: Use devm_*() functions
Use devm_*() functions to make cleanup paths simpler.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:28 -08:00
Jingoo Han
e8009ca036 mtd: nuc900_nand: Use devm_*() functions
Use devm_*() functions to make cleanup paths simpler.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:28 -08:00
Jingoo Han
133432a7e2 mtd: lpc32xx_slc: Use devm_*() functions
Use devm_*() functions to make cleanup paths simpler.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:28 -08:00
Jingoo Han
2281f7b63e mtd: denali_dt: Use devm_clk_get()
Use devm_clk_get() to make cleanup paths simpler.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:27 -08:00
Ezequiel Garcia
30b2afc847 mtd: nand: pxa3xx: Consolidate ECC initialization
In order to avoid code duplication, let's consolidate the ECC setting
for all SoC variants. Such decision is based on page size and ECC
strength requirements.

Also, provide a default value for the case where such ECC information
is not provided (non-ONFI devices).

Tested-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:27 -08:00
Ezequiel Garcia
5cbbdc6a9f mtd: nand: pxa3xx: Use extended cmdfunc() only if needed
Currently, we have two different cmdfunc's implementations:
one for PXA3xx SoC variant and one for Armada 370/XP SoC variant.

The former is the legacy one, typically constrained to devices
with page sizes smaller or equal to the controller's FIFO buffer.
On the other side, the latter _only_ supports the so-called extended
command semantics, which allow to handle devices with larger
page sizes (4 KiB, 8 KiB, ...).

This means we currently don't support devices with smaller pages on the
A370/XP SoC. Fix it by first renaming the cmdfuncs variants, and then
make the choice based on device page size (and SoC variant), rather than
SoC variant alone.

While at it, add a check for page size, to make sure we don't allow larger
pages sizes on the PXA3xx variant.

Tested-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:27 -08:00
Ezequiel Garcia
d20d0a6cf7 mtd: nand: pxa3xx: Clear need_wait flag when starting a command
Currently the driver assumes all commands will eventually trigger a RnB
transition, and thus a "device is ready" IRQ.

This assumption means that on every issued command, the dev_ready completion
handler is init'ed and the need_wait flag is set.

However this is incorrect: some commands (such as NAND_CMD_STATUS) don't
make the device 'busy' and thus a RnB transition never occurs.
Given, the NAND core never calls waitfunc() after such commands, this
is not a problem.

Therefore, it's possible to only clear the need_wait flag on every command
that is started.

This fixes a current bug that can be reproduced on PXA boards by writing
blank (all 0xff'ed) to a page:

  1. The kernel issues NAND_CMD_STATUS and sets need_wait=1. The flag
     won't be cleared for this command since no RnB transition is
     involved.

  2. NAND_CMD_PAGEPROG is issued but since the data is blank, the driver
     decides not to execute the command (and no IRQ activity is
     involved).

  3. The NAND core calls waitfunc() and waits for the dev_ready
     completion, which will never end since the device _is_ already ready.

Tested-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:26 -08:00