From mboxrd@z Thu Jan 1 00:00:00 1970 From: mturquette@linaro.org (Mike Turquette) Date: Mon, 01 Apr 2013 14:35:50 -0700 Subject: [PATCH RFC] clk: divider: Tolerate 0 divider for one based dividers In-Reply-To: References: <20130322171141.834.32801@quantum> <20130401182522.8177.96562@quantum> Message-ID: <20130401213550.8177.58990@quantum> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Quoting S?ren Brinkmann (2013-04-01 11:31:32) > Hi Mike, > > On Mon, Apr 01, 2013 at 11:25:22AM -0700, Mike Turquette wrote: > > Quoting S?ren Brinkmann (2013-03-22 11:00:15) > > > Since some of our dividers have a reset value of 0, I see this warning > > > during boot up. My intention here is to get rid of the warning for clocks > > > which deem 0 a valid divider value. > > > I thought, reusing the ONE_BASED flag might be okay, since all such > > > dividers have this redundant 0 state and might handle it similar. > > > Otherwise a new flag might be required. > > > > > > > Hi Soren, > > > > A flag will be necessary. I just checked some documentation for the > > divider outputs for OMAP's PLLs and (which use the common clk_divider > > type) and programming zero into those dividers is not allowed. At reset > > the divider registers are set to 1. > > > > So it is unsafe to simply reuse the ONE_BASED flag. > > > > Let's keep the current behavior as the default and introduce a new flag > > to handle the special case of a zero divider. Would you like to take a > > crack at it? It might also be nice to update the WARN message with a > > hint to take a look at your new flag in case future platforms hit the > > same issue as you. > Okay, sounds good. I should be able to get something ready within this > week. > Does anybody have suggestions for naming the new flag? > CLK_DIVIDER_ZERO_OKAY was my original suggestionn I think. > CLK_DIVIDER_ALLOW_ZERO sounds betterer to me. Regards, Mike > S?ren