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 <stable@vger.kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Цей коміт міститься в:
Dmitry Osipenko
2019-04-12 01:12:48 +03:00
зафіксовано Thierry Reding
джерело 76b959a44c
коміт b906c056b6

Переглянути файл

@@ -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);