From mboxrd@z Thu Jan 1 00:00:00 1970 From: tglx@linutronix.de (Thomas Gleixner) Date: Mon, 13 May 2013 21:30:30 +0200 (CEST) Subject: [RFC 2/8] ARM:global_timer: Add ARM global timer support. In-Reply-To: References: <1368022187-1633-1-git-send-email-srinivas.kandagatla@st.com> <1368022260-2197-1-git-send-email-srinivas.kandagatla@st.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, 13 May 2013, Linus Walleij wrote: > On Wed, May 8, 2013 at 4:11 PM, Srinivas KANDAGATLA > > + clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; > > + clk->set_mode = gt_clockevent_set_mode; > > + clk->set_next_event = gt_clockevent_set_next_event; > > + this_cpu_clk = __this_cpu_ptr(gt_evt); > > + *this_cpu_clk = clk; > > + clk->irq = gt_ppi; > > + clockevents_config_and_register(clk, gt_clk_rate, > > + 0xf, 0xffffffff); > > Why can't this clock event handle anything lower than 0xf? > Does that come from the datasheet or have you just copied some > code? > > Further, since this clock event hardware *most definately* supports > using a delta upper bound *beyond* 32 bits, I think the clock event > core code should be altered to allow for registereing such clock > events, but TGLX may have some idea here. This will work but will > not expose the full potential of this 64-bit counter hardware. That requires a full source tree sweep to change all set_next_event callbacks in one go. Easy to do with coccinelle, but that needs the proper timing, i.e. right after a -rc1. Thanks, tglx