From: Dmitry Osipenko Date: Thu, 11 Apr 2019 22:12:48 +0000 (+0300) Subject: memory: tegra: Fix integer overflow on tick value calculation X-Git-Tag: v5.2-rc1~44^2~11^2~3 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=b906c056b6023c390f18347169071193fda57dde;p=users%2Fjedix%2Flinux-maple.git memory: tegra: Fix integer overflow on tick value calculation 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 --- diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c index 1735e23dbc281..483ac3c1a762a 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);