From: Arnd Bergmann <arnd@arndb.de>
To: Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
Cc: robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com,
ijc+devicetree@hellion.org.uk, galak@codeaurora.org,
tj@kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org,
anirudh@xilinx.com, svemula@xilinx.com, punnaia@xilinx.com,
Anurag Kumar Vulisha <anuragku@xilinx.com>
Subject: Re: [RFC PATCH] drivers: ata: Read Rx water mark value from device-tree
Date: Sat, 20 Feb 2016 23:34:41 +0100 [thread overview]
Message-ID: <28916176.WDrPajhOPa@wuerfel> (raw)
In-Reply-To: <1455974302-7082-1-git-send-email-anuragku@xilinx.com>
On Saturday 20 February 2016 18:48:22 Anurag Kumar Vulisha wrote:
> index 7ca8b97..7e48dfc 100644
> --- a/Documentation/devicetree/bindings/ata/ahci-ceva.txt
> +++ b/Documentation/devicetree/bindings/ata/ahci-ceva.txt
> @@ -8,6 +8,7 @@ Required properties:
>
> Optional properties:
> - ceva,broken-gen2: limit to gen1 speed instead of gen2.
> + - ceva,rx-watermark: RX fifo water mark level for SATA controller.
>
> Examples:
> ahci@fd0c0000 {
> @@ -17,4 +18,5 @@ Examples:
> interrupts = <0 133 4>;
> clocks = <&clkc SATA_CLK_ID>;
> ceva,broken-gen2;
> + ceva,rx-watermark = <0x40>;
> };
>
How would a hardware integrator know which value is right for a
particular SoC?
Could it be keyed off the hardware ID? Could the bootloader
perhaps set an appropriate value in the AHCI_VEND_PTC
register at boot time and the driver read the initial
value from it?
>From the description, it sounds like this is a policy decision
rather than hardware description, and shouldn't really be
in here.
Arnd
next prev parent reply other threads:[~2016-02-20 22:35 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-20 13:18 [RFC PATCH] drivers: ata: Read Rx water mark value from device-tree Anurag Kumar Vulisha
2016-02-20 22:34 ` Arnd Bergmann [this message]
2016-02-22 10:53 ` Anurag Kumar Vulisha
2016-02-22 15:19 ` Arnd Bergmann
2016-02-23 5:58 ` Anurag Kumar Vulisha
2016-02-23 10:20 ` Arnd Bergmann
2016-02-23 15:29 ` Anurag Kumar Vulisha
2016-02-23 19:29 ` Rob Herring
2016-02-26 13:48 ` Anurag Kumar Vulisha
2016-03-02 5:53 ` Anurag Kumar Vulisha
2016-03-02 8:05 ` Michal Simek
2016-03-02 9:11 ` Arnd Bergmann
2016-03-02 9:27 ` Michal Simek
2016-03-02 11:42 ` Arnd Bergmann
2016-03-02 11:51 ` Michal Simek
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