| Message ID | 20241001125033.10625-7-johan+linaro@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | serial: qcom-geni: fix receiver enable | expand |
Hi, On Tue, Oct 1, 2024 at 5:51 AM Johan Hovold <johan+linaro@kernel.org> wrote: > > Drop the unnecessary WARN() in case the TTY buffers are ever full in > favour of a rate limited dev_err() which doesn't kill the machine when > panic_on_warn is set. > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> > --- > drivers/tty/serial/qcom_geni_serial.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c > index 5b6c5388efee..8bc4b240bf59 100644 > --- a/drivers/tty/serial/qcom_geni_serial.c > +++ b/drivers/tty/serial/qcom_geni_serial.c > @@ -570,9 +570,8 @@ static void handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop) > > ret = tty_insert_flip_string(tport, port->rx_buf, bytes); > if (ret != bytes) { > - dev_err(uport->dev, "%s:Unable to push data ret %d_bytes %d\n", > - __func__, ret, bytes); > - WARN_ON_ONCE(1); > + dev_err_ratelimited(uport->dev, "failed to push data (%d < %u)\n", > + ret, bytes); Not that it really matters, but since you're fixing the type of "bytes" to %u you probably should fix "ret" to %u too, which means changing the type of it? Officially tty_insert_flip_string returns the (unsigned) size_t. As a nit, I'd also say that your error message shouldn't assert "<" unless you change your "if" test to "<". It seems safer to use != so IMO the printout should also say "!=". I'd hope you're not hitting this error a lot because it means you're dropping bytes, but getting rid of the WARN_ON and changing to ratelimited makes sense to me. Reviewed-by: Douglas Anderson <dianders@chromium.org>
On Thu, Oct 03, 2024 at 01:06:43PM -0700, Doug Anderson wrote: > On Tue, Oct 1, 2024 at 5:51 AM Johan Hovold <johan+linaro@kernel.org> wrote: > > @@ -570,9 +570,8 @@ static void handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop) > > > > ret = tty_insert_flip_string(tport, port->rx_buf, bytes); > > if (ret != bytes) { > > - dev_err(uport->dev, "%s:Unable to push data ret %d_bytes %d\n", > > - __func__, ret, bytes); > > - WARN_ON_ONCE(1); > > + dev_err_ratelimited(uport->dev, "failed to push data (%d < %u)\n", > > + ret, bytes); > > Not that it really matters, but since you're fixing the type of > "bytes" to %u you probably should fix "ret" to %u too, which means > changing the type of it? Officially tty_insert_flip_string returns the > (unsigned) size_t. Yeah, that was changed recently, but apparently not all callers were updated. I'll just leave this as is for now too. > As a nit, I'd also say that your error message shouldn't assert "<" > unless you change your "if" test to "<". It seems safer to use != so > IMO the printout should also say "!=". Possibly, but if we ever hit that we have bigger problems. > I'd hope you're not hitting this error a lot because it means you're > dropping bytes, but getting rid of the WARN_ON and changing to > ratelimited makes sense to me. No, this was just something I noticed when reviewing the function. Johan
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 5b6c5388efee..8bc4b240bf59 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -570,9 +570,8 @@ static void handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop) ret = tty_insert_flip_string(tport, port->rx_buf, bytes); if (ret != bytes) { - dev_err(uport->dev, "%s:Unable to push data ret %d_bytes %d\n", - __func__, ret, bytes); - WARN_ON_ONCE(1); + dev_err_ratelimited(uport->dev, "failed to push data (%d < %u)\n", + ret, bytes); } uport->icount.rx += ret; tty_flip_buffer_push(tport);
Drop the unnecessary WARN() in case the TTY buffers are ever full in favour of a rate limited dev_err() which doesn't kill the machine when panic_on_warn is set. Signed-off-by: Johan Hovold <johan+linaro@kernel.org> --- drivers/tty/serial/qcom_geni_serial.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)