On Thu, Dec 12, 2013 at 06:31:43PM +0800, Chen-Yu Tsai wrote: > Hi, > > On Thu, Dec 12, 2013 at 5:04 PM, Maxime Ripard > <maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote: > > Hi, > > > > On Wed, Dec 11, 2013 at 02:45:08PM +0000, srinivas kandagatla wrote: > >> >>> 1. .tx_coe > >> >>> This is not exported in the DT bindings. > >> >>> Looking at stmmac code, not setting this seems to disable all > >> >>> checksum offloading. > >> >> > >> >> Why cant this go via DT as well? > >> > > >> > If you and Giuseppe are OK with this, why not? > >> Am Ok with it. > > > > Please note that I'm opposed to this until someone explain why putting > > it in the DT is relevant (and not just convenient). > > Checksum offloading is an optional feature[1], implemented starting > from version 3.20a. It is not tied to a specific IP version. As such, > using a "snps,dwmac-<version>" compatible isn't a good fit here. No, but we're not in such case. Since we have a compatible of our own, we can derive it from that. Putting a property in the DT would only be redundant. > stmmac does auto-detection for optional features on MAC version > 3.50a. > This is what Srinivas was referring to. > > Unfortunately, our MAC is < 3.50a. No auto-detection. We could add a > "snps,dwmac-tx-coe" compatible for this, or the seperate DT property. > > The other way would be to pass the flags in the initial .data with the > SoC specific compatible. Other SoCs with the same feature won't be > able to reuse the same compatible though. Which is already pretty much the case, since we have to deal with Allwinner specific code and features. A new compatible is cheap to maintain, a new property is not. Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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