core: kernel: fix big latency due to trace_ext_put() via. uart #7648
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When optee emits log, the NW interrupts are masked, if console_putc() is implemetned by writing to a uart, given uart slow characteristic, this could introduce a big NW irq latency. Though, this patch brings a side effect: trace_ext_put() may emit log simultenaously thus the log is hard to read. However, comparing the side effect between hard to read log and big NW irq latency, the NW irq latency is much more severe, we have to compromise here. Signed-off-by: Jisheng Zhang <[email protected]>
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An even easier fix is to disable logs from OP-TEE. |
Disabling log seems a big hammer, we want to keep some important logs such as tee panic log so that we can know what happened when the panic happens. |
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OP-TEE is supposed to be rather quiet when configured with loglevel error. |
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When optee emits log, the NW interrupts are masked, if console_putc() is implemetned by writing to a uart, given uart slow characteristic, this could introduce a big NW irq latency.
Though, this patch brings a side effect: trace_ext_put() may emit log simultenaously thus the log is hard to read. However, comparing the side effect between hard to read log and big NW irq latency, the NW irq latency is much more severe, we have to compromise here.