Re: [PATCH] mtd: rawnand: omap2: Actually prevent invalid configuration and build error

Guenter Roeck
2022-03-04T20:10:24Z

On 3/4/22 07:54, Miquel Raynal wrote:
> Hi Guenter, Roger,
>
> rdunlap@infradead.org wrote on Sat, 26 Feb 2022 22:55:28 -0800:
>
>> On 2/19/22 16:44, Guenter Roeck wrote:
>>> On Sat, Feb 19, 2022 at 09:36:00PM +0200, Roger Quadros wrote:
>>>> The root of the problem is that we are selecting symbols that have
>>>> dependencies. This can cause random configurations that can fail.
>>>> The cleanest solution is to avoid using select.
>>>>
>>>> This driver uses interfaces from the OMAP_GPMC driver so we have to
>>>> depend on it instead.
>>>>
>>>> Fixes: 4cd335dae3cf ("mtd: rawnand: omap2: Prevent invalid configuration and build error")
>>>> Signed-off-by: Roger Quadros <rogerq@kernel.org>
>>>
>>> Tested-by: Guenter Roeck <linux@roeck-us.net>
>>
>> Tested-by: Randy Dunlap <rdunlap@infradead.org>
>
> Sorry for noticing that just now, but there is still a problem with
> this patch: we now always compile-in the OMAP_GPMC driver whenever we
> need the NAND controller, even though it is not needed. This grows the
> kernel for no reason.
>

Sorry, you lost me.

> In fact, Roger once said:
>
> "We will figure out how to enable OMAP_GPMC for K3 architecture
> some other way."
>
> It turns out this is not what was finally proposed. Could we try yet
> another solution?
>
>>
>> Thanks.
>>
>>>
>>>> ---
>>>> drivers/mtd/nand/raw/Kconfig | 3 +--
>>>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
>>>> index 36e697456ec4..9b078e78f3fa 100644
>>>> --- a/drivers/mtd/nand/raw/Kconfig
>>>> +++ b/drivers/mtd/nand/raw/Kconfig
>>>> @@ -42,8 +42,7 @@ config MTD_NAND_OMAP2
>>>> tristate "OMAP2, OMAP3, OMAP4 and Keystone NAND controller"
>>>> depends on ARCH_OMAP2PLUS || ARCH_KEYSTONE || ARCH_K3 || COMPILE_TEST
>>>> depends on HAS_IOMEM
>>>> - select MEMORY
>>>> - select OMAP_GPMC
>>>> + depends on OMAP_GPMC

No matter if select or depend, both result in OMAP_GPMC enabled
if MTD_NAND_OMAP2={m,y}, and both suggest that OMAP_GPMC is
needed for MTD_NAND_OMAP2. That conflicts with

we now always compile-in the OMAP_GPMC driver whenever we
need the NAND controller, even though it is not needed
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

If it isn't needed, why the dependency in the first place ?
Also, commit 4cd335dae3cf2 states "this driver depends on OMAP_GPMC
driver and uses symbols from there". Are you saying that this is not
correct ?

Guenter