From: marex@denx•de (Marek Vasut)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 08/11] MTD: m25p80: Add option to limit SPI transfer size.
Date: Thu, 4 Jun 2015 01:03:09 +0200 [thread overview]
Message-ID: <201506040103.09555.marex@denx.de> (raw)
In-Reply-To: <8fc4b9f5291a509c4c35782a1337bf536f1019af.1433364398.git.hramrach@gmail.com>
On Wednesday, June 03, 2015 at 11:26:41 PM, Michal Suchanek wrote:
> On sunxi the SPI controller currently does not have DMA support and fails
> any transfer larger than 63 bytes.
>
> On Exynos the pl330 DMA controller fails any transfer larger than 64kb
> when using slower speed like 40MHz and any transfer larger than 128bytes
> when running at 133MHz.
This smells more like some corruption of the data on the bus or something
even more obscure.
> The best thing is that in both cases the controller can just lock up and
> never finish potentially leaving the hardware in unusable state.
>
> So it is required that the m25p80 driver actively prevents doing
> transfers that are too large for the current driver state on a
> particular piece of hardware.
>
> Signed-off-by: Michal Suchanek <hramrach@gmail•com>
>
> --
>
> Update commit message and documentation text.
> ---
> .../devicetree/bindings/mtd/jedec,spi-nor.txt | 6 ++++++
> drivers/mtd/devices/m25p80.c | 24
> ++++++++++++++++++++-- 2 files changed, 28 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt
> b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt index
> 2bee681..4e63ae8 100644
> --- a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt
> +++ b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt
> @@ -19,6 +19,12 @@ Optional properties:
> all chips and support for it can not be detected at
> runtime. Refer to your chips' datasheet to check if this is supported by
> your chip.
> +- linux,max_tx_len : With some SPI controller drivers possible transfer
> size is + limited. This may be hardware or driver bug.
> + Transfer data in chunks no larger than this value. +
> Using this option may severely degrade performance and
> + possibly flash memory life when max_tx_len is
> smaller than + flash page size (typically 256 bytes)
Will we need similar patch for all other SPI slave drivers, like SPI NAND ?
Best regards,
Marek Vasut
next prev parent reply other threads:[~2015-06-03 23:03 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-03 21:26 [PATCH 00/11] Enable access to SPI NOR flash on Samsung Snow board Michal Suchanek
2015-06-03 21:26 ` [PATCH 01/11] ARM: dt: Add SPI CS " Michal Suchanek
2015-06-04 2:05 ` Krzysztof Kozlowski
2015-06-04 6:52 ` Javier Martinez Canillas
2015-06-03 21:26 ` [PATCH 04/11] mtd: ofpart: do not fail probe when no partitions exist Michal Suchanek
2015-06-03 22:58 ` Marek Vasut
2015-06-04 4:54 ` Michal Suchanek
2015-06-04 15:28 ` Marek Vasut
2015-06-04 15:40 ` Michal Suchanek
2015-06-05 14:13 ` Marek Vasut
2015-06-23 18:26 ` Brian Norris
2015-06-03 21:26 ` [PATCH 02/11] mtd: spi-nor: Add GD25LQ32C 1.8V SPI NOR flash ID Michal Suchanek
2015-06-03 21:26 ` [PATCH 05/11] mtd: mtdpart: Do not fail mtd probe when parsing partitions fails Michal Suchanek
2015-06-03 21:26 ` [PATCH 03/11] mtd: add debug prints to mtdpart partition parser Michal Suchanek
2015-06-03 21:26 ` [PATCH 09/11] dma: pl330: fix wording in mcbufsz message Michal Suchanek
2015-06-04 2:10 ` Krzysztof Kozlowski
2015-06-08 11:07 ` Vinod Koul
2015-06-03 21:26 ` [PATCH 06/11] mtd: spi-nor: rework spi nor read and write Michal Suchanek
2015-06-03 21:26 ` [PATCH 08/11] MTD: m25p80: Add option to limit SPI transfer size Michal Suchanek
2015-06-03 23:03 ` Marek Vasut [this message]
2015-06-04 4:31 ` Michal Suchanek
2015-06-04 15:15 ` Marek Vasut
2015-06-04 6:42 ` Geert Uytterhoeven
2015-06-04 8:31 ` Michal Suchanek
2015-06-04 17:15 ` Richard Cochran
2015-07-15 9:45 ` Michal Suchanek
2015-07-15 11:52 ` Marek Vasut
2015-07-15 15:59 ` Brian Norris
2015-07-15 17:15 ` Marek Vasut
2015-07-16 1:19 ` Brian Norris
2015-07-16 1:44 ` Marek Vasut
2015-07-19 19:01 ` Michal Suchanek
2015-07-21 4:29 ` Vinod Koul
2015-07-21 8:14 ` Michal Suchanek
2015-07-22 4:49 ` Vinod Koul
2015-07-22 7:30 ` Michal Suchanek
2015-07-22 7:33 ` Marek Vasut
2015-07-22 7:45 ` Michal Suchanek
2015-07-22 7:58 ` Marek Vasut
2015-07-22 8:18 ` Michal Suchanek
2015-07-22 8:24 ` Marek Vasut
2015-07-22 8:38 ` Michal Suchanek
2015-07-22 9:01 ` Marek Vasut
2015-07-23 16:46 ` Michal Suchanek
2015-07-23 17:03 ` Michal Suchanek
2015-07-24 8:34 ` Marek Vasut
2015-07-24 11:20 ` Michal Suchanek
2015-07-27 9:46 ` Michal Suchanek
2015-07-27 17:43 ` Marek Vasut
2015-07-27 20:43 ` Michal Suchanek
2015-07-30 11:24 ` Marek Vasut
2015-07-30 12:18 ` Michal Suchanek
2015-07-30 12:33 ` Marek Vasut
2015-06-03 21:26 ` [PATCH 07/11] mtd: spi-nor: rework write loop Michal Suchanek
2015-06-03 21:26 ` [PATCH 11/11] dt: Exynos: add Snow SPI NOR node Michal Suchanek
2015-06-04 2:04 ` Krzysztof Kozlowski
2015-06-04 15:20 ` Marek Vasut
2015-06-17 12:19 ` Pavel Machek
2015-06-03 21:26 ` [PATCH 10/11] spi: add more debug prints in s3c64xx Michal Suchanek
2015-06-03 23:04 ` Marek Vasut
2015-06-04 9:16 ` Mark Brown
2015-06-04 9:30 ` Geert Uytterhoeven
2015-06-04 9:42 ` Mark Brown
2015-06-04 9:33 ` Michal Suchanek
2015-06-04 10:26 ` Mark Brown
2015-06-04 10:52 ` Michal Suchanek
2015-06-04 10:56 ` Mark Brown
2015-06-03 22:53 ` [PATCH 00/11] Enable access to SPI NOR flash on Samsung Snow board Marek Vasut
2015-06-04 4:21 ` Michal Suchanek
2015-06-04 15:29 ` Marek Vasut
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