From: Dmitry Osipenko <digetx@gmail.com>
To: Thierry Reding <thierry.reding@gmail.com>,
Jonathan Hunter <jonathanh@nvidia.com>
Cc: linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v1 2/4] memory: tegra: Fix integer overflow on tick value calculation
Date: Fri, 12 Apr 2019 01:12:48 +0300 [thread overview]
Message-ID: <20190411221250.23233-3-digetx@gmail.com> (raw)
In-Reply-To: <20190411221250.23233-1-digetx@gmail.com>
Multiplying the Memory Controller clock rate by the tick count results
in an integer overflow and in result the truncated tick value is being
programmed into hardware, such that the GR3D memory client performance is
reduced by two times.
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/memory/tegra/mc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index 60474597180b..89e463952b8a 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -285,7 +285,7 @@ static int tegra_mc_setup_latency_allowance(struct tegra_mc *mc)
u32 value;
/* compute the number of MC clock cycles per tick */
- tick = mc->tick * clk_get_rate(mc->clk);
+ tick = (unsigned long long)mc->tick * clk_get_rate(mc->clk);
do_div(tick, NSEC_PER_SEC);
value = readl(mc->regs + MC_EMEM_ARB_CFG);
--
2.21.0
next prev parent reply other threads:[~2019-04-11 22:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-11 22:12 [PATCH v1 0/4] memory: tegra: Fix memory arbitration programming Dmitry Osipenko
2019-04-11 22:12 ` [PATCH v1 1/4] memory: tegra: Fix missed registers values latching Dmitry Osipenko
2019-04-11 22:12 ` Dmitry Osipenko [this message]
2019-04-11 22:12 ` [PATCH v1 3/4] memory: tegra: Replace readl-writel with mc_readl-mc_writel Dmitry Osipenko
2019-04-11 22:12 ` [PATCH v1 4/4] Revert "ARM: tegra: Restore memory arbitration on resume from LP1 on Tegra30+" Dmitry Osipenko
2019-04-18 9:37 ` [PATCH v1 0/4] memory: tegra: Fix memory arbitration programming Thierry Reding
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