[ Upstream commit 908b050114d8fefdddc57ec9fbc213c3690e7f5f ]
When I got my clock parenting slightly wrong I ended up with a crash
that looked like this:
Unable to handle kernel NULL pointer dereference at virtual
address 0000000000000000
...
pc : clk_hw_get_rate+0x14/0x44
...
Call trace:
clk_hw_get_rate+0x14/0x44
_freq_tbl_determine_rate+0x94/0xfc
clk_rcg2_determine_rate+0x2c/0x38
clk_core_determine_round_nolock+0x4c/0x88
clk_core_round_rate_nolock+0x6c/0xa8
clk_core_round_rate_nolock+0x9c/0xa8
clk_core_set_rate_nolock+0x70/0x180
clk_set_rate+0x3c/0x6c
of_clk_set_defaults+0x254/0x360
platform_drv_probe+0x28/0xb0
really_probe+0x120/0x2dc
driver_probe_device+0x64/0xfc
device_driver_attach+0x4c/0x6c
__driver_attach+0xac/0xc0
bus_for_each_dev+0x84/0xcc
driver_attach+0x2c/0x38
bus_add_driver+0xfc/0x1d0
driver_register+0x64/0xf8
__platform_driver_register+0x4c/0x58
msm_drm_register+0x5c/0x60
...
It turned out that clk_hw_get_parent_by_index() was returning NULL and
we weren't checking. Let's check it so that we don't crash.
Fixes: ac269395cdd8 ("clk: qcom: Convert to clk_hw based provider APIs")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lkml.kernel.org/r/20200203103049.v4.1.I7487325fe8e701a68a07d3be8a6a4b571eca9cfa@changeid
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit efd164b5520afd6fb2883b68e0d408a7de29c491 ]
Some RCGs (the gfx_3d_src_clk in msm8998 for example) are basically just
some constant ratio from the input across the entire frequency range. It
would be great if we could specify the frequency table as a single entry
constant ratio instead of a long list, ie:
{ .src = P_GPUPLL0_OUT_EVEN, .pre_div = 3 },
{ }
So, lets support that.
We need to fix a corner case in qcom_find_freq() where if the freq table
is non-null, but has no frequencies, we end up returning an "entry" before
the table array, which is bad. Then, we need ignore the freq from the
table, and instead base everything on the requested freq.
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Link: https://lkml.kernel.org/r/20191031185715.15504-1-jeffrey.l.hugo@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
