interconnect: qcom: sc7180: Drop IP0 interconnects
The IPA BCM resource ("IP0") on sc7180 was moved to the clk-rpmh driver in commit bcd63d22 ("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 7d3b0b0d ("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 b95b668e ("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: b95b668e ("interconnect: qcom: icc-rpmh: Add BCMs to commit list in pre_aggregate") Fixes: bcd63d22 ("clk: qcom: rpmh: Add IPA clock for SC7180") Fixes: 7d3b0b0d ("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.orgSigned-off-by: Georgi Djakov <djakov@kernel.org>
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