From a5b2e4b6ac21396af60c9b652be1fdbd04fe33e3 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Fri, 12 Apr 2019 01:12:48 +0300 Subject: [PATCH] memory: tegra: Fix integer overflow on tick value calculation commit b906c056b6023c390f18347169071193fda57dde upstream. 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 Signed-off-by: Dmitry Osipenko Signed-off-by: Thierry Reding Signed-off-by: Greg Kroah-Hartman --- 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 6ab481ee8ece..8ac02b6c162f 100644 --- a/drivers/memory/tegra/mc.c +++ b/drivers/memory/tegra/mc.c @@ -72,7 +72,7 @@ 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);