The IPA BCM resource ("IP0") on sc7180 was moved to the clk-rpmh driver
in commit bcd63d222b ("clk: qcom: rpmh: Add IPA clock for SC7180") and
modeled as a clk, but this interconnect driver still had it modeled as
an interconnect. This was mostly OK because nobody used the interconnect
definition, until the interconnect framework started dropping bandwidth
requests on interconnects that aren't used via the sync_state callback
in commit 7d3b0b0d81 ("interconnect: qcom: Use icc_sync_state"). Once
that patch was applied the IP0 resource was going to be controlled from
two places, the clk framework and the interconnect framework.
Even then, things were probably going to be OK, because commit
b95b668eaa ("interconnect: qcom: icc-rpmh: Add BCMs to commit list in
pre_aggregate") was needed to actually drop bandwidth requests on unused
interconnects, of which the IPA was one of the interconnect that wasn't
getting dropped to zero. Combining the three commits together leads to
bad behavior where the interconnect framework is disabling the IP0
resource because it has no users while the clk framework thinks the IP0
resource is on because the only user, the IPA driver, has turned it on
via clk_prepare_enable(). Depending on when sync_state is called, we can
get into a situation like below:
IPA driver probes
IPA driver gets notified modem started
runtime PM get()
IPA clk enabled -> IP0 resource is ON
sync_state runs
interconnect zeroes out the IP0 resource -> IP0 resource is off
IPA driver tries to access a register and blows up
The crash is an unclocked access that manifest as an SError.
SError Interrupt on CPU0, code 0xbe000011 -- SError
CPU: 0 PID: 3595 Comm: mmdata_mgr Not tainted 5.17.1+ #166
Hardware name: Google Lazor (rev1 - 2) with LTE (DT)
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : mutex_lock+0x4c/0x80
lr : mutex_lock+0x30/0x80
sp : ffffffc00da9b9c0
x29: ffffffc00da9b9c0 x28: 0000000000000000 x27: 0000000000000000
x26: ffffffc00da9bc90 x25: ffffff80c2024010 x24: ffffff80c2024000
x23: ffffff8083100000 x22: ffffff80831000d0 x21: ffffff80831000a8
x20: ffffff80831000a8 x19: ffffff8083100070 x18: 00000000ffff0a00
x17: 000000002f7254f1 x16: 0000000000000100 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
x11: 000000000001f0b8 x10: ffffffc00931f0b8 x9 : 0000000000000000
x8 : 0000000000000000 x7 : fefefefefeff2f60 x6 : 0000808080808080
x5 : 0000000000000000 x4 : 8080808080800000 x3 : ffffff80d2d4ee28
x2 : ffffff808c1d6e40 x1 : 0000000000000000 x0 : ffffff8083100070
Kernel panic - not syncing: Asynchronous SError Interrupt
CPU: 0 PID: 3595 Comm: mmdata_mgr Not tainted 5.17.1+ #166
Hardware name: Google Lazor (rev1 - 2) with LTE (DT)
Call trace:
dump_backtrace+0xf4/0x114
show_stack+0x24/0x30
dump_stack_lvl+0x64/0x7c
dump_stack+0x18/0x38
panic+0x150/0x38c
nmi_panic+0x88/0xa0
arm64_serror_panic+0x74/0x80
do_serror+0x0/0x80
do_serror+0x58/0x80
el1h_64_error_handler+0x34/0x4c
el1h_64_error+0x78/0x7c
mutex_lock+0x4c/0x80
__gsi_channel_start+0x50/0x17c
gsi_channel_start+0x54/0x90
ipa_endpoint_enable_one+0x34/0xc0
ipa_open+0x4c/0x120
Remove all IP0 resource management from the interconnect driver so that
clk-rpmh is the sole owner. This fixes the issue by preventing the
interconnect driver from overwriting the IP0 resource data that the
clk-rpmh driver wrote.
Cc: Alex Elder <elder@linaro.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Taniya Das <quic_tdas@quicinc.com>
Cc: Mike Tipton <quic_mdtipton@quicinc.com>
Fixes: b95b668eaa ("interconnect: qcom: icc-rpmh: Add BCMs to commit list in pre_aggregate")
Fixes: bcd63d222b ("clk: qcom: rpmh: Add IPA clock for SC7180")
Fixes: 7d3b0b0d81 ("interconnect: qcom: Use icc_sync_state")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Tested-by: Alex Elder <elder@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220412220033.1273607-2-swboyd@chromium.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>
2f3724930e