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: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
[olof: fixed calculation of printed values]
Signed-off-by: Olof Johansson <olof@lixom.net>
Add device tree support to the emc driver, filling in the platform data
based on the DT bindings.
Changes since v1:
* Unmangled some messed up patch squashes, moving changes to earlier patches
* Flipped an of_property_read_u32 return value test
* Clarified clock settings message on case where no table is provided
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Stephen Warren <swarren@nvidia.com>
This is the first step in making it device-tree aware and get rid of the
in-kernel EMC tables (of which there are none in mainline, thankfully).
Changes since v3:
* moved to devm_request_and_ioremap() in probe()
Changes since v2:
* D'oh -- missed a couple of variables that were added, never used and then
later removed in a later patch.
Changes since v1:
* Fixed messed up indentation
* Removed code that should be gone (was added here and removed later in series)
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Stephen Warren <swarren@nvidia.com>
The frequency memory bus on Tegra can be adjusted without
disabling accesses to memory by updating the memory
configuration registers from a per-board table, and then
changing the clock frequency. The clock controller and
memory controller have an interlock that prevents the
new memory registers from taking effect until the
clock frequency change.
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Colin Cross <ccross@android.com>
Stephen Warren
Olof Johansson
Colin Cross