Re: [PATCH] mtd: rawnand: atmel: Unmap streaming DMA mappings

From: Thorsten Leemhuis <regressions@leemhuis.info>
To: Tudor Ambarus <tudor.ambarus@microchip.com>,
	miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com,
	peda@axentia.se
Cc: nicolas.ferre@microchip.com, alexandre.belloni@bootlin.com,
	claudiu.beznea@microchip.com, bbrezillon@kernel.org,
	linux-mtd@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH] mtd: rawnand: atmel: Unmap streaming DMA mappings
Date: Wed, 17 Aug 2022 11:28:29 +0200	[thread overview]
Message-ID: <f041e45a-679c-5633-f855-9be0974d0086@leemhuis.info> (raw)
In-Reply-To: <20220728074014.145406-1-tudor.ambarus@microchip.com>

On 28.07.22 09:40, Tudor Ambarus wrote:
> Every dma_map_single() call should have its dma_unmap_single() counterpart,
> because the DMA address space is a shared resource and one could render the
> machine unusable by consuming all DMA addresses.
> 
> Cc: stable@vger.kernel.org
> Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

This afaics is missing the following tag:

Link:
https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/

These tags are considered important by Linus[1] and others, as they
allow anyone to look into the backstory weeks or years from now. That is
why they should be placed in cases like this, as
Documentation/process/submitting-patches.rst and
Documentation/process/5.Posting.rst explain in more detail. I care
personally, because these tags make my regression tracking efforts a
whole lot easier, as they allow my tracking bot 'regzbot' to
automatically connect reports with patches posted or committed to fix
tracked regressions.

[1] see for example:
https://lore.kernel.org/all/CAHk-=wjMmSZzMJ3Xnskdg4+GGz=5p5p+GSYyFBTh0f-DgvdBWg@mail.gmail.com/
https://lore.kernel.org/all/CAHk-=wgs38ZrfPvy=nOwVkVzjpM3VFU1zobP37Fwd_h9iAD5JQ@mail.gmail.com/
https://lore.kernel.org/all/CAHk-=wjxzafG-=J8oT30s7upn4RhBs6TX-uVFZ5rME+L5_DoJA@mail.gmail.com/

Apropos regzbot, let me tell regzbot to monitor this thread:

#regzbot ^backmonitor:
https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I deal with a lot of
reports and sometimes miss something important when writing mails like
this. If that's the case here, don't hesitate to tell me in a public
reply, it's in everyone's interest to set the public record straight.