From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp.megiteam.pl ([31.186.83.105]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hgst8-0002o2-4D for barebox@lists.infradead.org; Fri, 28 Jun 2019 15:34:13 +0000 From: Marcin Niestroj Date: Fri, 28 Jun 2019 17:33:49 +0200 Message-Id: <20190628153350.16250-2-m.niestroj@grinn-global.com> In-Reply-To: <20190628153350.16250-1-m.niestroj@grinn-global.com> References: <20190628153350.16250-1-m.niestroj@grinn-global.com> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH 2/3] clk: divider: Fix best div calculation for power-of-two and table dividers To: barebox@lists.infradead.org Cc: Marcin Niestroj commit dd23c2cd38da2c64af381b19795d2c4f115e8ecb Linux upstream. clk: divider: Fix best div calculation for power-of-two and table dividers The divider returned by clk_divider_bestdiv() is likely to be invalid in case of power-of-two and table dividers when CLK_SET_RATE_PARENT flag isn't set. Fixes boot on STiH416 platform. Signed-off-by: Maxime Coquelin Signed-off-by: Mike Turquette [mturquette@linaro.org: trivial merge conflict & updated changelog] Signed-off-by: Marcin Niestroj --- drivers/clk/clk-divider.c | 36 +++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index 84a5322cf..d705729af 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -141,6 +141,37 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div) return true; } +static int _round_up_table(const struct clk_div_table *table, int div) +{ + const struct clk_div_table *clkt; + int up = _get_table_maxdiv(table); + + for (clkt = table; clkt->div; clkt++) { + if (clkt->div == div) + return clkt->div; + else if (clkt->div < div) + continue; + + if ((clkt->div - div) < (up - div)) + up = clkt->div; + } + + return up; +} + +static int _div_round_up(struct clk_divider *divider, + unsigned long parent_rate, unsigned long rate) +{ + int div = DIV_ROUND_UP(parent_rate, rate); + + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + div = __roundup_pow_of_two(div); + if (divider->table) + div = _round_up_table(divider->table, div); + + return div; +} + static int clk_divider_bestdiv(struct clk *clk, unsigned long rate, unsigned long *best_parent_rate) { @@ -156,7 +187,7 @@ static int clk_divider_bestdiv(struct clk *clk, unsigned long rate, if (!(clk->flags & CLK_SET_RATE_PARENT)) { parent_rate = *best_parent_rate; - bestdiv = DIV_ROUND_UP(parent_rate, rate); + bestdiv = _div_round_up(divider, parent_rate, rate); bestdiv = bestdiv == 0 ? 1 : bestdiv; bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv; return bestdiv; @@ -230,6 +261,9 @@ static int clk_divider_set_rate(struct clk *clk, unsigned long rate, div = DIV_ROUND_UP(parent_rate, rate); } + if (!_is_valid_div(divider->table, div, divider->flags)) + return -EINVAL; + value = _get_val(divider, div); if (value > div_mask(divider)) -- 2.21.0 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox