We already know that there are controllers not able to read the three
copies of the parameter page in one go. The workaround was to first
request the controller to assert command and address cycles on the
NAND bus to trigger a parameter page read, and then do a read
operation for each page.
But there are also controllers which are not able to split the
parameter page read between the command/address cycles and the actual
data operation.
Let's use a regular PARAMETER PAGE READ operation for the first
iteration and use eithe a CHANGE READ COLUMN or a simple DATA READ
operation for the following copies, depending on what the controller
supports. The default for non-exec-op compliant drivers remains
unchanged: use a SIMPLE READ.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200507105241.14299-11-miquel.raynal@bootlin.com
We already know that there are controllers not able to read the three
copies of the parameter page in one go. The workaround was to first
request the controller to assert command and address cycles on the
NAND bus to trigger a parameter page read, and then do a simple read
operation for each page.
But there are also controllers which are not able to split the
parameter page read between the command/address cycles and the actual
data operation.
Let's use a regular PARAMETER PAGE READ operation for the first
iteration and use either a CHANGE READ COLUMN or a simple DATA READ
operation for the following copies, depending on what the controller
supports. The default behavior for non-exec-op compliant drivers
remains the same: DATA READ.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200507105241.14299-10-miquel.raynal@bootlin.com
The logic in nand_do_read_ops() is to use a bufpoi variable, either
set to the original buffer, or set to a bounce buffer which in the end
happens to be chip->data_buf depending on the value of the
use_bounce_buf boolean. This is not a reason to call chip->data_buf
directly when we know that we are using the bounce buffer. Let's use
bufpoi instead to be consistent.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200507105241.14299-7-miquel.raynal@bootlin.com
Both in nand_do_read_ops() and nand_do_write_ops() there is a boolean
called use_bufpoi which is set to true in case of unaligned request or
when there is a need for a DMA-able buffer. It basically means "use a
bounce buffer".
Depending on the value of use_bufpoi, the bufpoi variable is always
used and will either point to the original buffer or to the nand_chip
structure "internal data buffer" (this buffer is allocated with
kmalloc() on purpose so that it will be DMA-compliant).
In all cases bufpoi is used so the boolean name is misleading. Rename
use_bufpoi to be use_bouce_buf to be more accurate.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200507105241.14299-6-miquel.raynal@bootlin.com
NAND controller drivers can set the NAND_USE_BOUNCE_BUFFER flag to a
chip 'option' field. With this flag, the core is responsible of
providing DMA-able buffers.
The current behavior is to not force the use of a bounce buffer when
the core thinks this is not needed. So in the end the name is a bit
misleading, because in theory we will always have a DMA buffer but in
practice it will not always be a bounce buffer.
Rename this flag NAND_USES_DMA to be more accurate.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200507105241.14299-4-miquel.raynal@bootlin.com
During detection the logic on the NAND bus is:
/* Regular ONFI detection */
1/ read the three NAND parameter pages
/* Extended parameter page detection */
2/ send "read the NAND parameter page" commands without reading
actual data
3/ move the column pointer to the extended page and read it
If fact, as long as there is nothing happening on the NAND bus between
1/ and 3/, the operation 2/ is redundant so remove it.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200428094302.14624-8-miquel.raynal@bootlin.com
During ONFI detection, the CRC derived from the parameter page and the
CRC supposed to be at the end of the parameter page are compared. If
they do not match, the second then the third copies of the page are
tried.
The current implementation compares the newly derived CRC with the CRC
contained in the first page only. So if this particular CRC area has
been corrupted, then the detection will fail for a wrong reason.
Fix this issue by checking the derived CRC against the right one.
Fixes: 39138c1f4a ("mtd: rawnand: use bit-wise majority to recover the ONFI param page")
Cc: stable@vger.kernel.org
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200428094302.14624-4-miquel.raynal@bootlin.com
In a previous fix, I changed the condition on which the timeout of an
IRQ is reached from:
if (!ret)
into:
if (ret && !pending)
While having a non-zero return code is usual in the Linux kernel, here
ret comes from a wait_for_completion_timeout() which returns 0 when
the waiting period is too long.
Hence, the revised condition should be:
if (!ret && !pending)
The faulty patch did not produce any error because of the !pending
condition so this change is finally purely cosmetic and does not
change the actual driver behavior.
Fixes: cafb56dd74 ("mtd: rawnand: marvell: prevent timeouts on a loaded machine")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200424164501.26719-2-miquel.raynal@bootlin.com
The Denali IP have several registers to specify how many clock cycles
should be waited between falling/rising signals. You can improve the
NAND access performance by programming these registers with optimized
values.
Because struct nand_sdr_timings represents the device requirement
in pico seconds, denali_setup_data_interface() computes the register
values by dividing the device timings with the clock period.
Marek Vasut reported this driver in the latest kernel does not work
on his SOCFPGA board. (The on-board NAND chip is mode 5)
The suspicious parameter is acc_clks, so this commit relaxes it.
The Denali NAND Flash Memory Controller User's Guide describes this
register as follows:
acc_clks
signifies the number of bus interface clk_x clock cycles,
controller should wait from read enable going low to sending
out a strobe of clk_x for capturing of incoming data.
Currently, acc_clks is calculated only based on tREA, the delay on the
chip side. This does not include additional delays that come from the
data path on the PCB and in the SoC, load capacity of the pins, etc.
This relatively becomes a big factor on faster timing modes like mode 5.
Before supporting the ->setup_data_interface() hook (e.g. Linux 4.12),
the Denali driver hacks acc_clks in a couple of ways [1] [2] to support
the timing mode 5.
We would not go back to the hard-coded acc_clks, but we need to include
this factor into the delay somehow. Let's say the amount of the additional
delay is 10000 pico sec.
In the new calculation, acc_clks is determined by timings->tREA_max +
data_setup_on_host.
Also, prolong the RE# low period to make sure the data hold is met.
Finally, re-center the data latch timing for extra safety.
[1] https://github.com/torvalds/linux/blob/v4.12/drivers/mtd/nand/denali.c#L276
[2] https://github.com/torvalds/linux/blob/v4.12/drivers/mtd/nand/denali.c#L282
Reported-by: Marek Vasut <marex@denx.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Marek Vasut <marex@denx.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200317071821.9916-1-yamada.masahiro@socionext.com
