From:   Nikita Travkin <nikita@trvn.ru>
To:     mturquette@baylibre.com, sboyd@kernel.org, linus.walleij@linaro.org
Cc:     bjorn.andersson@linaro.org, agross@kernel.org, tdas@codeaurora.org,
        joonwoop@codeaurora.org, svarbanov@mm-sol.com,
        linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org,
        linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
        ~postmarketos/upstreaming@lists.sr.ht,
        Nikita Travkin <nikita@trvn.ru>
Subject: [PATCH 2/4] clk: qcom: clk-rcg2: Make sure to not write d=0 to the NMD register
Date:   Thu,  9 Dec 2021 21:37:18 +0500
Message-Id: <20211209163720.106185-3-nikita@trvn.ru>
In-Reply-To: <20211209163720.106185-1-nikita@trvn.ru>
References: <20211209163720.106185-1-nikita@trvn.ru>
MIME-Version: 1.0
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Sometimes calculation of d value may result in 0 because of the
rounding after integer division. This causes the following error:

[  113.969689] camss_gp1_clk_src: rcg didn't update its configuration.
[  113.969754] WARNING: CPU: 3 PID: 35 at drivers/clk/qcom/clk-rcg2.c:122 update_config+0xc8/0xdc

Make sure that D value is never zero.

Fixes: 7f891faf596e ("clk: qcom: clk-rcg2: Add support for duty-cycle for RCG")
Signed-off-by: Nikita Travkin <nikita@trvn.ru>
---
 drivers/clk/qcom/clk-rcg2.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
index 6964cf914b60..fdfd43e2a01b 100644
--- a/drivers/clk/qcom/clk-rcg2.c
+++ b/drivers/clk/qcom/clk-rcg2.c
@@ -424,6 +424,10 @@ static int clk_rcg2_set_duty_cycle(struct clk_hw *hw, struct clk_duty *duty)
 	if (d > mask)
 		d = mask;
 
+	/* Hardware can't handle d=0, make sure it's at least 1 */
+	if (!d)
+		d = 1;
+
 	if ((d / 2) > (n - m))
 		d = (n - m) * 2;
 	else if ((d / 2) < (m / 2))
-- 
2.30.2