linux-kernel - Re: [PATCH v4 0/3] request_firmware() into pre-allocated buffers

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Date:	Tue, 7 Jun 2016 09:45:14 +0100
From:	Russell King - ARM Linux <linux@...linux.org.uk>
To:	Stephen Boyd <stephen.boyd@...aro.org>
Cc:	linux-kernel@...r.kernel.org, Ming Lei <ming.lei@...onical.com>,
	Vikram Mulukutla <markivx@...eaurora.org>,
	Mark Brown <broonie@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Mimi Zohar <zohar@...ux.vnet.ibm.com>,
	linux-arm@...ts.infradead.org
Subject: Re: [PATCH v4 0/3] request_firmware() into pre-allocated buffers

And you're still doing it, after I've already pointed out that you
posted these to linux-arm and not linux-arm-kernel.  By posting them
to the wrong list, you are preventing proper review of these patches,
so really these should not be merged until you've corrected that.

On Tue, Jun 07, 2016 at 01:35:34AM -0700, Stephen Boyd wrote:
> Some systems are memory constrained but they need to load very
> large firmwares. The firmware subsystem allows drivers to request
> this firmware be loaded from the filesystem, but this requires
> that the entire firmware be loaded into kernel memory first
> before it's provided to the driver. This can lead to a situation
> where we map the firmware twice, once to load the firmware into
> kernel memory and once to copy the firmware into the final
> resting place.
> 
> This design creates needless memory pressure and delays loading
> because we have to copy from kernel memory to somewhere else.
> This patch sets adds support to the request firmware API to load the
> firmware directly into a pre-allocated buffer, skipping the intermediate
> copying step and alleviating memory pressure during firmware loading.
> The drawback is that we can't use the firmware caching feature because
> the memory for the firmware cache is not managed by the firmware
> layer.
> 
> Patches based on v4.7-rc1.
> 
> Changes since v3:
>  * Rebased onto v4.7-rc1
>  * Renamed enum per Mimi's comment
> 
> Changes since v2:
>  * Dropped DMA API changes and moved to dma coherent APIs per Catalin's
>    suggestions
>  * Reworked to request firmware directly into any pre-allocated buffer
>  * Split off cleanup patch into patch #1 to ease review 
>  * Added file reading enum for reading firmware directly into buffer
> 
> Changes since v1:
>  * Rebased onto v4.6-rc1 (large conflicts due to movement of code from Mimi)
>  * Added some CONFIG_HAS_DMA ifdefs around code that's using DMA ops
> 
> 
> Stephen Boyd (2):
>   firmware: Consolidate kmap/read/write logic
>   firmware: Support loading into a pre-allocated buffer
> 
> Vikram Mulukutla (1):
>   firmware: Provide infrastructure to make fw caching optional
> 
>  drivers/base/firmware_class.c | 183 +++++++++++++++++++++++++++++-------------
>  fs/exec.c                     |   9 ++-
>  include/linux/firmware.h      |   8 ++
>  include/linux/fs.h            |   1 +
>  4 files changed, 142 insertions(+), 59 deletions(-)
> 
> -- 
> 2.9.0-rc1
> 
> 
> _______________________________________________
> linux-arm mailing list
> linux-arm@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm

-- 
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