Re: [PATCH 02/28] spi: spi-mem: Create a repeated address operation

From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Tudor Ambarus <tudor.ambarus@linaro.org>
Cc: Mark Brown <broonie@kernel.org>,
	 Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	 Pratyush Yadav <pratyush@kernel.org>,
	 Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	Steam Lin <STLin2@winbond.com>,  Santhosh Kumar K <s-k6@ti.com>,
	linux-spi@vger.kernel.org,  linux-kernel@vger.kernel.org,
	linux-mtd@lists.infradead.org
Subject: Re: [PATCH 02/28] spi: spi-mem: Create a repeated address operation
Date: Wed, 19 Nov 2025 18:10:50 +0100	[thread overview]
Message-ID: <871pluc5id.fsf@bootlin.com> (raw)
In-Reply-To: <0be97b27-4f8b-4d22-a653-154e87ecbc78@linaro.org> (Tudor Ambarus's message of "Wed, 5 Nov 2025 16:43:58 +0100")

Hi Tudor,

First, thank you very much for all this precious feedback! I am happy to
get feedback not only on the spi-mem side, but also on the NAND changes!

On 05/11/2025 at 16:43:58 +01, Tudor Ambarus <tudor.ambarus@linaro.org> wrote:

> On 10/31/25 6:26 PM, Miquel Raynal wrote:
>> In octal DTR mode, while the command opcode is *always* repeated,
>
> this info is wrong: opcode can be repeated, inverted or a dedicated 16bit,
> so please fix this to not mislead readers

I didn't know :) But yeah I had SPI NAND mind which was obviously
wrong. I'll correct.

>> addresses may either be long enough to cover at least two bytes (in
>> which case the existing macro works), or otherwise for single byte
>> addresses, the byte must also be duplicated and sent twice: on each
>> front of the clock. Create a macro for this common case.
>> 
>> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
>> ---
>>  include/linux/spi/spi-mem.h | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>> 
>> diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
>> index 81c9c7e793b6ab894675e0198d412d84b8525c2e..e4db0924898ce5b17d2b6d4269495bb968db2871 100644
>> --- a/include/linux/spi/spi-mem.h
>> +++ b/include/linux/spi/spi-mem.h
>> @@ -43,6 +43,14 @@
>>  		.dtr = true,					\
>>  	}
>>  
>> +#define SPI_MEM_DTR_OP_RPT_ADDR(__val, __buswidth)		\
>
> I find the name too generic. This is an macro for 1 byte addresses,
> right?

Yes it is. The name mimics the "dtr command repeat" macro name. Maybe
you want to include the info that it is  carrying a single byte? maybe
"*RPT_SINGLE_BYTE_ADDR"? but that's a big too long IMO. Any other idea?

Thanks,
Miquèl

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