[PATCH v2 0/3] media: camss: Link CAMSS power domain on MSM8996

Yassine Oudjana
2023-05-26T18:07:42Z

From: Yassine Oudjana <y.oudjana@protonmail.com>

CAMSS on MSM8996 has been broken since commit
46cc03175498 ("media: camss: Split power domain management").
This would happen when trying to start streaming:

[ 199.097810] ------------[ cut here ]------------
[ 199.097893] camss_top_ahb_clk status stuck at 'off'
[ 199.097913] WARNING: CPU: 3 PID: 728 at drivers/clk/qcom/clk-branch.c:91 clk_branch_wait+0x140/0x160
...
[ 199.100064] clk_branch_wait+0x140/0x160
[ 199.100112] clk_branch2_enable+0x30/0x40
[ 199.100159] clk_core_enable+0x6c/0xb0
[ 199.100211] clk_enable+0x2c/0x50
[ 199.100257] camss_enable_clocks+0x94/0xe0 [qcom_camss]
[ 199.100342] csiphy_set_power+0x154/0x2a0 [qcom_camss]
...
[ 199.101594] ---[ end trace 0000000000000000 ]---
[ 199.101736] qcom-camss a34000.camss: clock enable failed: -16
[ 199.101813] qcom-camss a34000.camss: Failed to power up pipeline: -16

Turns out camss_top_ahb_clk needs the CAMSS power domain to be on. Before
the change, VFE power domains were enabled before CSIPHY enabled clocks,
and since the CAMSS power domain was their parent, it got enabled as well.
With the VFE power domains now enabled after CSIPHY is powered on, the
CAMSS power domain remains off and things go south when CSIPHY tries to
enable camss_top_ahb_clk.

Link the CAMSS power domain in camss_configure_pd to make sure it gets
enabled before CSIPHY tries to enable clocks.

Changes since v1:
- Wrap commit messages at 75 lines.
- Remove duplicate "media" from and shorten the subject of the first
patch.
- Expand the commit message of the second patch.
- Fix "Fixes" tag in the third patch as well as other commit references.

Yassine Oudjana (3):
dt-bindings: media: camss: qcom,msm8996-camss: Add CAMSS power domain
arm64: dts: qcom: msm8996: Add CAMSS power domain and
power-domain-names to CAMSS
media: camss: Link CAMSS power domain

.../bindings/media/qcom,msm8996-camss.yaml | 13 ++++++++++++-
arch/arm64/boot/dts/qcom/msm8996.dtsi | 4 +++-
drivers/media/platform/qcom/camss/camss.c | 9 ++++++++-
3 files changed, 23 insertions(+), 3 deletions(-)

--
2.40.1