From: rogerq@ti•com (Roger Quadros)
To: linux-arm-kernel@lists•infradead.org
Subject: Antwort: Re: [PATCH 2/2] memory: omap-gpmc: Add Kconfig option for debug
Date: Wed, 2 Sep 2015 17:43:34 +0300 [thread overview]
Message-ID: <55E70B16.8050301@ti.com> (raw)
In-Reply-To: <OFFEAB70E0.C9C6AAC7-ONC1257EB3.0049139E-C1257EB3.004A5089@br-automation.com>
On 01/09/15 16:31, Hannes Schmelzer wrote:
>> Hi Hannes,
> Hi Roger,
>
>>
>> On 27/08/15 08:52, Hannes Schmelzer wrote:
>>> Hi Tony,
>>>
>>> Did anyone test this changeset on some AM335x board?
>>>
>>> Today I ran into trouble with that because:
>>>
>>> The GPMC controller gets reseted on kernel boot due to the
> missing/removed
>> HWMOD_INIT_NO_RESET flag.
>>>
>>> Primary this should not be a big problem, but on my board (maybe on
> all
>> AM335x) the GPMC doesn't behave as described in TRM.
>>> Especially the GPMC_CONFIG register is not reset to 0h after reset,
> instead
>> it holds the value 0xa00 which is very strange because bit 10-31 are
> reserved.
>>>
>>> Further this 0xa00 means that Bit9 (WAIT1PINPOLARITY) is set, exactly
> this
>> causes my system to stall on first access the connected NAND flash
> because it
>> never becomes ready due to the wrong wait pin polarity. Maybe others
> dont't
>> run into trouble because they may use WAIT0PIN, which one has it's old
> polarity.
>>
>> So nand ready/busy pin is connected to waitpin1 through an inverter on
> your board?
>>
>> On am335x-evm we use waitpin0. Nand ready/busy is directly connected to
> waitpin0.
>
> No there is no inverter between flash and AM335x, the READY_nBUSY line is
> directly connected to waitpin1.
> But your sentence brings some good idea to me, i will try to solder some
> inverter into the READY_nBUSY line on my board and see if the problem
> appears again.
Please don't do that. We want to maintain the NAND ready/busy# logic as it is.
> If i'm right in my theory that the value 0xa00 in GPMC_CONFIG register is
> the problem, the inverter would solve it.
You really need to disable read/write monitoring in gpmc-settings.
>
> You're right am335x-evm uses waitpin0, which one is not affected from this
> "bug".
Why is it not affected by this bug? The polarities are same for am335x-evm and
your board. Only the wait pin is different.
> I have to use waitpin1, because i also have a 2nd ethernet interface
> connected, and there is waitpin0 uses for collission detect signal from
> the phy (other pinmux).
>
>> For NAND operation read/write wait monitoring must be disabled.
>> The nand driver uses the WAIT pin purely for Read/Busy signalling.
>> Unfortunately the existing driver cannot handle anything other than
> waitpin 0
>> for nand for DT boot.
> for sure ? have a look to omap-gpmc.c at line #90.
> Here i can see that either can be used.
Which tree are you referring to?
>
>>
>> I've tried to address this issue here
>> http://thread.gmane.org/gmane.linux.drivers.devicetree/131076
> This is useful if the READY_nBUSY line cannot be connected to the GPMC
> itself, instead it maybe connected to some other gpio.
> But it doesn't solve the problem.
It does. We are adding gpiolib and interrupt controller support for all
the wait pins.
cheers,
-roger
next prev parent reply other threads:[~2015-09-02 14:43 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-20 21:21 [PATCH 0/2] omap gpmc changes for parsing devices and working debug Tony Lindgren
2015-05-20 21:21 ` [PATCH 1/2] memory: omap-gpmc: Fix parsing of devices Tony Lindgren
2015-05-20 21:21 ` [PATCH 2/2] memory: omap-gpmc: Add Kconfig option for debug Tony Lindgren
2015-05-20 22:50 ` Paul Walmsley
2015-05-20 22:56 ` Tony Lindgren
2015-05-21 1:06 ` Paul Walmsley
2015-08-27 6:25 ` Hannes Schmelzer
[not found] ` <OFCA2F1DCE.C787A961-ONC1257EAE.001D79BC-C1257EAE.00203AFF@br-automation.com>
2015-08-27 16:59 ` Tony Lindgren
2015-08-28 4:44 ` Hannes Schmelzer
2015-09-01 12:35 ` Roger Quadros
2015-09-01 13:31 ` Antwort: " Hannes Schmelzer
2015-09-02 14:43 ` Roger Quadros [this message]
2015-09-01 12:35 ` Roger Quadros
2016-01-01 11:29 ` Ivaylo Dimitrov
2016-01-04 17:02 ` Tony Lindgren
2016-01-04 17:34 ` Pali Rohár
2016-01-04 17:40 ` Tony Lindgren
2016-01-04 18:59 ` Ivaylo Dimitrov
2016-01-05 4:13 ` Tony Lindgren
2016-01-05 8:49 ` Pali Rohár
2016-01-05 22:49 ` Tony Lindgren
2016-01-06 8:55 ` Ivaylo Dimitrov
2016-01-06 9:05 ` Pali Rohár
2016-01-06 16:44 ` Tony Lindgren
2016-01-06 17:36 ` Aaro Koskinen
2016-01-06 17:40 ` Sebastian Reichel
2016-01-06 17:47 ` Tony Lindgren
2016-01-06 18:01 ` Ivaylo Dimitrov
2016-01-06 18:26 ` Tony Lindgren
2016-01-06 18:39 ` Ivaylo Dimitrov
2016-01-07 18:07 ` Tony Lindgren
2016-01-07 21:45 ` Ivaylo Dimitrov
2016-01-08 2:26 ` Tony Lindgren
2016-01-08 5:13 ` Ivaylo Dimitrov
2016-01-08 7:59 ` Pali Rohár
2016-01-09 0:23 ` Ivaylo Dimitrov
2016-01-21 9:14 ` Pali Rohár
2016-02-02 9:33 ` Ivaylo Dimitrov
2016-02-02 23:39 ` Tony Lindgren
2016-02-03 0:00 ` Tony Lindgren
2016-02-03 7:03 ` Ivaylo Dimitrov
2016-02-03 16:50 ` Ivaylo Dimitrov
2016-02-05 6:10 ` Tony Lindgren
2016-02-05 14:43 ` Ivaylo Dimitrov
2016-01-08 17:10 ` Tony Lindgren
2016-01-08 7:56 ` Pali Rohár
2016-01-08 17:04 ` Tony Lindgren
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