On Tue, Oct 04, 2016 at 05:11:12PM +0530, Raju Lakkaraju wrote: > From: Raju Lakkaraju <Raju.Lakkaraju@xxxxxxxxxxxxx> > > Edge-rate: > As system and networking speeds increase, a signal's output transition, > also know as the edge rate or slew rate (V/ns), takes on greater importance > because high-speed signals come with a price. That price is an assortment of > interference problems like ringing on the line, signal overshoot and > undershoot, extended signal settling times, crosstalk noise, transmission > line reflections, false signal detection by the receiving device and > electromagnetic interference (EMI) -- all of which can negate the potential > gains designers are seeking when they try to increase system speeds through > the use of higher performance logic devices. The fact is, faster signaling > edge rates can cause a higher level of electrical noise or other type of > interference that can actually lead to slower line speeds and lower maximum > system frequencies. This parameter allow the board designers to change the > driving strange, and thereby change the EMI behavioral. > > Edge-rate parameters (vddmac, edge-slowdown) get from Device Tree. > > Tested on Beaglebone Black with VSC 8531 PHY. > > Signed-off-by: Raju Lakkaraju <Raju.Lakkaraju@xxxxxxxxxxxxx> > > --- > All the review comments updated and resending for review. > > Change set: > v1: > - Initial version of Edge-rate driver add by using IOCTL. > v2: > - Changed edge-rate parameter to Device Tree with magic number. > v3: > - Added Device Tree documentati0n and edge-rate parameter table. > Added probe function initialize the vsc8531 private data structure. > v4: > - As per review comment, Device Tree parameters (vddmac, edge-slowdown) > added. > v5: > - As per review comment, Device Tree Document parameters (vddmac, > edge-slowdown) real numbers added. Table number changed from 5 to 1. > v6: > - As per review comment, Removed Device Tree header file. Removed MACROs > and add ARRAYSIZE But you ignored my request to make the table values positive, and to enforce an exact match in the table. NACK Andrew -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
