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When a remoteproc has crashed, rproc_report_crash() is called to handle whatever recovery is desired. This can happen at almost any time, often triggered by an interrupt, though it can also be initiated by a write to debugfs file remoteproc/remoteproc*/crash. When a crash is reported, the crash handler worker is scheduled to run (rproc_crash_handler_work()). One thing that worker does is call rproc_trigger_recovery(), which calls rproc_stop(). That calls the ->stop method for any remoteproc subdevices before making the remote processor go offline. The Q6V5 modem remoteproc driver implements an SSR subdevice that notifies registered drivers when the modem changes operational state (prepare, started, stop/crash, unprepared). The IPA driver registers to receive these notifications. With that as context, I'll now describe the problem. There was a situation in which buggy modem firmware led to a modem crash very soon after system (AP) resume had begun. The crash caused a remoteproc SSR crash notification to be sent to the IPA driver. The problem was that, although system resume had begun, it had not yet completed, and the IPA driver was still in a suspended state. This scenario could happen to any driver that registers for these SSR notifications, because they are delivered without knowledge of the (suspend) state of registered recipient drivers. This patch offers a simple fix for this, by having the crash handling worker function run on the system freezable workqueue. This workqueue does not operate if user space is frozen (for suspend). As a result, the SSR subdevice only delivers its crash notification when the system is fully operational (i.e., neither suspended nor in suspend/resume transition). Signed-off-by: Alex Elder <elder@linaro.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro> Tested-by: Siddharth Gupta <sidgup@codeaurora.org> Bug: 190545349 Change-Id: Ic9b81757f07eea0930480ff5e08a38d92a843606 Link: https://lore.kernel.org/linux-remoteproc/20210519234418.1196387-2-elder@linaro.org/ Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> |
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| .. | ||
| da8xx_remoteproc.c | ||
| imx_rproc.c | ||
| ingenic_rproc.c | ||
| Kconfig | ||
| keystone_remoteproc.c | ||
| Makefile | ||
| mtk_common.h | ||
| mtk_scp_ipi.c | ||
| mtk_scp.c | ||
| omap_remoteproc.c | ||
| omap_remoteproc.h | ||
| qcom_common.c | ||
| qcom_common.h | ||
| qcom_pil_info.c | ||
| qcom_pil_info.h | ||
| qcom_q6v5_adsp.c | ||
| qcom_q6v5_mss.c | ||
| qcom_q6v5_pas.c | ||
| qcom_q6v5_wcss.c | ||
| qcom_q6v5.c | ||
| qcom_q6v5.h | ||
| qcom_sysmon.c | ||
| qcom_wcnss_iris.c | ||
| qcom_wcnss.c | ||
| qcom_wcnss.h | ||
| remoteproc_cdev.c | ||
| remoteproc_core.c | ||
| remoteproc_coredump.c | ||
| remoteproc_debugfs.c | ||
| remoteproc_elf_helpers.h | ||
| remoteproc_elf_loader.c | ||
| remoteproc_internal.h | ||
| remoteproc_sysfs.c | ||
| remoteproc_virtio.c | ||
| st_remoteproc.c | ||
| st_slim_rproc.c | ||
| stm32_rproc.c | ||
| ti_k3_dsp_remoteproc.c | ||
| ti_k3_r5_remoteproc.c | ||
| ti_sci_proc.h | ||
| wkup_m3_rproc.c | ||