[PATCH] serial: serial-tegra: reduce irq-latency after rx errors
DORMANTno replies
LANDED
From: Randolph Maaßen <hidden>
Date: 2020-06-05 15:07:42
Also in:
linux-tegra, lkml
Subsystem:
tegra serial driver, the rest, tty layer and serial drivers · Maintainers:
Laxman Dewangan, Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
Landed in mainline as f1681a9a2a62 on 2020-06-27.
Since dev_err() calls can lead to synchronous writes to another serial console these calls can provide significant latency during irq-handling in tegra_uart_isr(). With this latency another interrupt is likely to apper during handling of the first interrupt, which might lock up the kernel completely. These errors are reported to the error counters so converting the dev_err() to dev_dbg() is appropriate. Signed-off-by: Randolph Maaßen <redacted> --- drivers/tty/serial/serial-tegra.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index 8de8bac9c6c7..d3fef5ab289a 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c@@ -439,16 +439,16 @@ static char tegra_uart_decode_rx_error(struct tegra_uart_port *tup, /* Overrrun error */ flag = TTY_OVERRUN; tup->uport.icount.overrun++; - dev_err(tup->uport.dev, "Got overrun errors\n"); + dev_dbg(tup->uport.dev, "Got overrun errors\n"); } else if (lsr & UART_LSR_PE) { /* Parity error */ flag = TTY_PARITY; tup->uport.icount.parity++; - dev_err(tup->uport.dev, "Got Parity errors\n"); + dev_dbg(tup->uport.dev, "Got Parity errors\n"); } else if (lsr & UART_LSR_FE) { flag = TTY_FRAME; tup->uport.icount.frame++; - dev_err(tup->uport.dev, "Got frame errors\n"); + dev_dbg(tup->uport.dev, "Got frame errors\n"); } else if (lsr & UART_LSR_BI) { /* * Break error
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2.11.0