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From: Mark Brown <broonie@kernel.org>
To: Serge Semin <fancer.lancer@gmail.com>
Cc: Tudor Ambarus <tudor.ambarus@microchip.com>,
	linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] spi: Limit the spi device max speed to controller's max speed
Date: Wed, 9 Dec 2020 20:25:52 +0000	[thread overview]
Message-ID: <20201209202552.GE4790@sirena.org.uk> (raw)
In-Reply-To: <20201209201535.32g4kwpzo45jiqr3@mobilestation>

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On Wed, Dec 09, 2020 at 11:15:35PM +0300, Serge Semin wrote:
> On Wed, Dec 09, 2020 at 07:54:20PM +0000, Mark Brown wrote:

> > Right, in general we aim to do this sort of fixup on the transfers
> > and messages rather than the devices, I guess we might be missing
> > validation in some of the flash acceleration paths or was this an issue
> > seen through inspection?

> In case of DW SPI driver we just make sure the SPI-client device
> speed set in the max_speed_hz doesn't exceed the controller SPI-bus
> clock frequency and clamp it if it does. So the driver is safe in that
> matter.

Ideally the driver wouldn't have to check though (no harm in doing so of
course).

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  reply	other threads:[~2020-12-09 20:26 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-09 17:35 [PATCH] spi: Limit the spi device max speed to controller's max speed Tudor Ambarus
2020-12-09 19:46 ` Serge Semin
2020-12-09 19:54   ` Mark Brown
2020-12-09 20:15     ` Serge Semin
2020-12-09 20:25       ` Mark Brown [this message]
2020-12-09 20:30         ` Serge Semin
2020-12-10  8:58           ` Tudor.Ambarus
2020-12-10 15:33             ` Mark Brown
2020-12-10 16:32               ` Tudor.Ambarus
2020-12-10 18:16                 ` Mark Brown
2020-12-11 17:51 ` Mark Brown
2020-12-15 14:24   ` Geert Uytterhoeven
2020-12-16  8:25     ` Tudor.Ambarus

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