Messages in this thread |  | | From | Arnd Bergmann <> | Subject | Re: [RFC PATCH] drivers: ata: Read Rx water mark value from device-tree | Date | Sat, 20 Feb 2016 23:34:41 +0100 |
| |
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
|  |