This patch set fixes hang during system resume which started coming
after adding Memory Interconnect and OPP support to the Tegra194 CPUFREQ
in below change:
f41e1442ac5b ("cpufreq: tegra194: add OPP support and set bandwidth").
Tegra194 CPUFREQ driver uses 'CPUFREQ_NEED_INITIAL_FREQ_CHECK' flag
which causes a CPU frequency set request from the 'cpuhp_cpufreq_online'
hotplug notifier during resume. The CPU frequency set call also triggers
a DRAM bandwidth set request but the BPMP driver hasn't resumed yet
which results in hang during resume.
Fix this by resetting the BPMP IPC channels inside tegra_bpmp_transfer*()
API if the bandwidth request came from CPU clusters and the BPMP driver
is still suspended.
---
v[1] -> v2:
- add suspend hook instead of reset hook based approach.
- add suspended instead of needs_reset flag in 'struct tegra_bpmp'.
- add flags field to 'struct tegra_bpmp_message'.
- set TEGRA_BPMP_MESSAGE_RESET flag from MC driver for CPU BW request.
- use suspended and flags to reset BPMP IPC early on resume.
Sumit Gupta (1):
firmware: tegra: add suspend hook and reset BPMP IPC early on resume
Thierry Reding (1):
memory: tegra: set BPMP msg flags to reset IPC channels
drivers/firmware/tegra/bpmp.c | 30 ++++++++++++++++++++++++++++++
drivers/memory/tegra/tegra234.c | 4 ++++
include/soc/tegra/bpmp.h | 6 ++++++
3 files changed, 40 insertions(+)
[1] https://lore.kernel.org/linux-tegra/20230830115829.23977-1-sumitg@xxxxxxxxxx/
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2.17.1
