Commit 76c2f6e5 authored by Stephen Warren's avatar Stephen Warren Committed by Olof Johansson

ARM: tegra: Fix EMC pdata initialization from registers

Commit d91eeb0 "ARM: tegra: emc: device tree support" modified the EMC
driver to create an EMC table from existing register settings when none
was provided through platform data or device tree. This code wrote the
wrong clock rate into the table; the actual rate in Hz, rather than the
expected half-rate in KHz. This caused the BUG_ON in
tegra2_emc_clk_round_rate() to fire, since that enormous rate could not
be generated.

Fixes:

[    2.425921] kernel BUG at arch/arm/mach-tegra/tegra2_clocks.c:1158!
...
[    2.618766] [<c001c0e8>] (tegra2_emc_clk_round_rate+0x58/0x70) from [<c00198b4>] (clk_round_rate+0x48/0x68)
[    2.628494] [<c00198b4>] (clk_round_rate+0x48/0x68) from [<c0019cc0>] (clk_set_rate_locked+0x40/0x68)
[    2.637707] [<c0019cc0>] (clk_set_rate_locked+0x40/0x68) from [<c0019d10>] (clk_set_rate+0x28/0x40)
[    2.646754] [<c0019d10>] (clk_set_rate+0x28/0x40) from [<c001ffc8>] (tegra_update_cpu_speed+0x54/0x144)
[    2.656144] [<c001ffc8>] (tegra_update_cpu_speed+0x54/0x144) from [<c002016c>] (tegra_target+0xb4/0xe0)
[    2.665538] [<c002016c>] (tegra_target+0xb4/0xe0) from [<c01a96c0>] (__cpufreq_driver_target+0x88/0xa4)
[    2.674931] [<c01a96c0>] (__cpufreq_driver_target+0x88/0xa4) from [<c01ac9d0>] (dbs_check_cpu+0x324/0x340)
[    2.684582] [<c01ac9d0>] (dbs_check_cpu+0x324/0x340) from [<c01aca40>] (do_dbs_timer+0x54/0xf4)
[    2.693277] [<c01aca40>] (do_dbs_timer+0x54/0xf4) from [<c00369a8>] (process_one_work+0x1d4/0x320)
[    2.702225] [<c00369a8>] (process_one_work+0x1d4/0x320) from [<c0036f34>] (worker_thread+0x134/0x230)
[    2.711437] [<c0036f34>] (worker_thread+0x134/0x230) from [<c003add0>] (kthread+0x80/0x8c)
[    2.719700] [<c003add0>] (kthread+0x80/0x8c) from [<c000ebf4>] (kernel_thread_exit+0x0/0x8)
Reported-by: default avatarMarc Dietrich <marvin24@gmx.de>
Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
[olof: fixed calculation of printed values]
Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
parent 3391811c
......@@ -284,16 +284,16 @@ static struct tegra_emc_pdata __devinit *tegra_emc_fill_pdata(struct platform_de
pdata->tables = devm_kzalloc(&pdev->dev, sizeof(*pdata->tables),
GFP_KERNEL);
pdata->tables[0].rate = clk_get_rate(c);
pdata->tables[0].rate = clk_get_rate(c) / 2 / 1000;
for (i = 0; i < TEGRA_EMC_NUM_REGS; i++)
pdata->tables[0].regs[i] = emc_readl(emc_reg_addr[i]);
pdata->num_tables = 1;
khz = pdata->tables[0].rate / 1000;
khz = pdata->tables[0].rate;
dev_info(&pdev->dev, "no tables provided, using %ld kHz emc, "
"%ld kHz mem\n", khz, khz/2);
"%ld kHz mem\n", khz * 2, khz);
return pdata;
}
......
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