linux-kernel - [PATCH v3 20/20] clk: tegra: pll: Fix issues with rates for VCO PLLs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1430506447-29074-21-git-send-email-rklein@nvidia.com>
Date:	Fri, 1 May 2015 14:54:07 -0400
From:	Rhyland Klein <rklein@...dia.com>
To:	Peter De Schrijver <pdeschrijver@...dia.com>
CC:	Mike Turquette <mturquette@...aro.org>,
	Stephen Warren <swarren@...dotorg.org>,
	Stephen Boyd <sboyd@...eaurora.org>,
	Thierry Reding <thierry.reding@...il.com>,
	Alexandre Courbot <gnurou@...il.com>,
	linux-clk@...r.kernel.org, linux-tegra@...r.kernel.org,
	linux-kernel@...r.kernel.org, Rhyland Klein <rklein@...dia.com>,
	Andrew Bresticker <abrestic@...omium.org>
Subject: [PATCH v3 20/20] clk: tegra: pll: Fix issues with rates for VCO PLLs

From: Andrew Bresticker <abrestic@...omium.org>

Without this change clk_get_rate would return the final output
rather than the VCO output as it would factor in the pdiv when
it shouldn't. This will cause problems for all dividers in the
subtree of the VCO PLL.

Signed-off-by: Andrew Bresticker <abrestic@...omium.org>
Signed-off-by: Rhyland Klein <rklein@...dia.com>
---
v3:
  - Added fix for this bug which was found during testing

 drivers/clk/tegra/clk-pll.c |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
index 44bdbbac361d..8953573b5bcd 100644
--- a/drivers/clk/tegra/clk-pll.c
+++ b/drivers/clk/tegra/clk-pll.c
@@ -723,6 +723,8 @@ static int clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 		spin_lock_irqsave(pll->lock, flags);
 
 	_get_pll_mnp(pll, &old_cfg);
+	if (pll->params->vco_out)
+		cfg.p = old_cfg.p;
 
 	if (old_cfg.m != cfg.m || old_cfg.n != cfg.n || old_cfg.p != cfg.p ||
 		old_cfg.sdm_data != cfg.sdm_data)
@@ -782,11 +784,15 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hw,
 
 	_get_pll_mnp(pll, &cfg);
 
-	pdiv = _hw_to_p_div(hw, cfg.p);
-	if (pdiv < 0) {
-		WARN(1, "Clock %s has invalid pdiv value : 0x%x\n",
-			__clk_get_name(hw->clk), cfg.p);
+	if (pll->params->vco_out) {
 		pdiv = 1;
+	} else {
+		pdiv = _hw_to_p_div(hw, cfg.p);
+		if (pdiv < 0) {
+			WARN(1, "Clock %s has invalid pdiv value : 0x%x\n",
+				__clk_get_name(hw->clk), cfg.p);
+			pdiv = 1;
+		}
 	}
 
 	if (pll->params->set_gain)
@@ -1073,6 +1079,8 @@ static int clk_pllxc_set_rate(struct clk_hw *hw, unsigned long rate,
 		spin_lock_irqsave(pll->lock, flags);
 
 	_get_pll_mnp(pll, &old_cfg);
+	if (pll->params->vco_out)
+		cfg.p = old_cfg.p;
 
 	if (old_cfg.m != cfg.m || old_cfg.n != cfg.n || old_cfg.p != cfg.p)
 		ret = _program_pll(hw, &cfg, rate);
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/