Re: (subset) [PATCH v7 00/11] spi: spi-mem: Convert Aspeed SMC driver to spi-mem

From: "Cédric Le Goater" <clg@kaod.org>
To: Pratyush Yadav <p.yadav@ti.com>, Mark Brown <broonie@kernel.org>
Cc: <linux-spi@vger.kernel.org>, <linux-mtd@lists.infradead.org>,
	<andrew@aj.id.au>, <robh+dt@kernel.org>,
	<devicetree@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>, <richard@nod.at>,
	<joel@jms.id.au>, <tudor.ambarus@microchip.com>,
	<miquel.raynal@bootlin.com>, <chin-ting_kuo@aspeedtech.com>,
	<linux-aspeed@lists.ozlabs.org>, <vigneshr@ti.com>,
	<linux-kernel@vger.kernel.org>
Subject: Re: (subset) [PATCH v7 00/11] spi: spi-mem: Convert Aspeed SMC driver to spi-mem
Date: Tue, 17 May 2022 14:03:02 +0200	[thread overview]
Message-ID: <a17b2446-f5a6-d606-8ef4-3931b8bc94da@kaod.org> (raw)
In-Reply-To: <20220517110509.2e6xbwot63yl6a3c@ti.com>

Pratyush,

On 5/17/22 13:05, Pratyush Yadav wrote:
> Hi Cedric,
> 
> On 16/05/22 07:39PM, Mark Brown wrote:
>> On Mon, 9 May 2022 19:56:05 +0200, Cédric Le Goater wrote:
>>> This series adds a new SPI driver using the spi-mem interface for the
>>> Aspeed static memory controllers of the AST2600, AST2500 and AST2400
>>> SoCs.
>>>
>>>   * AST2600 Firmware SPI Memory Controller (FMC)
>>>   * AST2600 SPI Flash Controller (SPI1 and SPI2)
>>>   * AST2500 Firmware SPI Memory Controller (FMC)
>>>   * AST2500 SPI Flash Controller (SPI1 and SPI2)
>>>   * AST2400 New Static Memory Controller (also referred as FMC)
>>>   * AST2400 SPI Flash Controller (SPI)
>>>
>>> [...]
>>
>> Applied to
>>
>>     https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next
>>
>> Thanks!
>>
>> [02/11] dt-bindings: spi: Convert the Aspeed SMC controllers device tree binding
>>          commit: ce9858ea499da025684a7a5f19823c2c3f14bdce
>> [03/11] spi: spi-mem: Convert Aspeed SMC driver to spi-mem
>>          commit: 9c63b846e6df43e5b3d31263f7db545f32deeda3
>> [04/11] spi: aspeed: Add support for direct mapping
>>          commit: 9da06d7bdec7dad8018c23b180e410ef2e7a4367
>> [05/11] spi: aspeed: Adjust direct mapping to device size
>>          commit: bb084f94e1bca4a5c4f689d7aa9b410220c1ed71
>> [06/11] spi: aspeed: Workaround AST2500 limitations
>>          commit: 5785eedee42c34cfec496199a80fa8ec9ddcf7fe
>> [07/11] spi: aspeed: Add support for the AST2400 SPI controller
>>          commit: 53526ab27d9c256504f267713aea60db7af18fb0
>> [08/11] spi: aspeed: Calibrate read timings
>>          commit: eeaec1ea05c0e0f08e04c6844f20cc24a2fcc0f4
> 
> I have repeatedly objected to this patch [0][1][2] and you have
> repeatedly decided to not address my objections. 

That's a very harsh way of saying things. I did not decide anything
or ignore your comments. I answered your questions and acknowledged
that indeed the read training was done under the dirmap handler but
this was not a concern today since we had all the required information
from spimem.

We waited _together_, 5 or 6 weeks, for more inputs on how to address
the concerns you raised regarding the sustainability of this method.

> I won't spend any more time fighting it. 

This is not a fight. I don't know why you interpret it that way.

Now, since you object so explicitly, and since this patchset has
not reached the Linux kernel yet, we should consider dropping it.
I rather do that than push crap in mainline. But then, please,
provide solutions and not only objections !

> But I will say that you should not expect any
> guarantees that SPI NOR or SPI NAND will not break your calibration in
> the future if they decide to move the dirmap_create() call around.

If that's the case one day, we have multiple solutions :

   - stop doing the training
   - move the training to the appropriate handler if it exists
   - use a default value

>> [11/11] mtd: spi-nor: aspeed: set the decoding size to at least 2MB for AST2600
>>          commit: 73ae97e3cabb580639f02f12a192324a53c4bebb
>>
> 
> [0] https://patchwork.kernel.org/project/spi-devel-general/patch/20220325100849.2019209-9-clg@kaod.org/
> [1] https://patchwork.kernel.org/project/spi-devel-general/patch/20220214094231.3753686-9-clg@kaod.org/
> [2] https://lore.kernel.org/all/20220208190636.h6dubktkmuosvdxo@ti.com/

Regards,

Cédric.