[PATCH v2 0/8] MTD: xway: fix driver

[Hauke Mehrtens]

On 06/19/2016 02:50 PM, Boris Brezillon wrote:
> Hi Hauke,
> 
> On Sat, 18 Jun 2016 21:14:04 +0200
> Hauke Mehrtens <hauke at hauke-m.de> wrote:
> 
>> Without these patches the driver does not work for me.
>> Some of these patches are in OpenWrt for years now and should go 
>> upstream. In addition this converts it from some hack with the 
>> plat_nand driver to a normal platform driver.
> 
> Thanks for the cleanup.
> 
> Still, I think we could go further. For example, you could get rid of
> the IO_R/W_ADDR assignment and have your own ->iomem field in
> xway_nand_data.

Ok that should be possible.

> And I'd also like to see a clean nand_controller/nand_chip separation,
> as done in other drivers (brcm, sunxi, qcom, ...), and that would be
> even better if you could support a new binding where the NAND
> controller and NAND chip are properly separated.
> Note that these changes can be done incrementally and won't prevent the
> inclusion of the patches you've already posted.
> 
> The last thing that is really bothering me is the ebu spinlock and its
> implications on the whole system responsiveness.
> 
> Could you tell me more about this EBU. Do you really have to make it a
> spinlock, and do you really have to disable irqs?

The External Bus unit (EBU) is used to connect NAND and API flash chips
and is used in some strange setups as a GPIO controller.

I will try to make it a mutex and see what happens.

> 
> Regards,
> 
> Boris
> 
>>
>> changes since:
>> v1:
>>  - convert to normal platform driver
>>  - do not use global variable xway_latchcmd
>>  - use mtd_to_nand()
>>
>> Hauke Mehrtens (4):
>>   MTD: xway: convert to normal platform driver
>>   MTD: xway: add some more documentation
>>   MTD: xway: extract read and write function
>>   MTD: xway: use global NAND_CMD_RESET define
>>
>> John Crispin (4):
>>   MTD: xway: the latched command should be persistent
>>   MTD: xway: remove endless loop
>>   MTD: xway: add missing write_buf and read_buf to nand driver
>>   MTD: xway: fix nand locking
>>
>>  drivers/mtd/nand/Kconfig     |   1 -
>>  drivers/mtd/nand/xway_nand.c | 206 ++++++++++++++++++++++++++++++-------------
>>  2 files changed, 147 insertions(+), 60 deletions(-)
>>
>