@@ -345,20 +345,22 @@ long omap2_dpll_round_rate(struct clk_hw *hw, unsigned long target_rate,
pr_debug("clock: %s: m = %d: n = %d: new_rate = %ld\n",
clk_name, m, n, new_rate);
- if (target_rate == new_rate) {
+ if ((new_rate <= target_rate) &&
+ (new_rate > dd->last_rounded_rate)) {
dd->last_rounded_m = m;
dd->last_rounded_n = n;
- dd->last_rounded_rate = target_rate;
- break;
+ dd->last_rounded_rate = new_rate;
+ if (new_rate == target_rate)
+ break;
}
}
- if (target_rate != new_rate) {
+ if (!dd->last_rounded_rate) {
pr_debug("clock: %s: cannot round to rate %ld\n",
clk_name, target_rate);
return ~0;
}
- return target_rate;
+ return dd->last_rounded_rate;
}
Currently round rate function would return proper rate iff requested rate exactly matches the PLL lockable rate. This causes set_rate to fail if exact rate could not be set. Instead round rate may return closest rate possible (less than the requested). And if any user is badly in need of exact rate, then return value of round rate could be used to decide whether to invoke set rate or not. Modify round rate so that it return closest possible rate. This was required to get display working on am335x. Without this display rate could not be set (taking help of SET_RATE_PARENT). Couple of the downstream clocks of display PLL are basic clock dividers and they do MULT_ROUND_UP before requesting rate on PLL causing values that mostly could not be locked by PLL. And even otherwise, if requested rate for a particular pixel clock could not be satisfied by PLL, display would not work. This change will resolve the issue. Signed-off-by: Afzal Mohammed <afzal@ti.com> --- arch/arm/mach-omap2/clkt_dpll.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)