| Message ID | 20180321025241.19785-3-jk@ozlabs.org |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | serial: implement flow control for ASPEED VUART driver | expand |
On Wed, Mar 21, 2018 at 10:52:38AM +0800, Jeremy Kerr wrote: > The buf_overrun count is only every written, and not exposed to > userspace anywhere. This means that dropped characters due to flip > buffer overruns are never visible to userspace. > > The /proc/tty/driver/serial file exports a bunch of metrics (including > hardware overruns) already, so add the buf_overrun (as "bo:") to this > file. > > Signed-off-by: Jeremy Kerr <jk@ozlabs.org> > --- > drivers/tty/serial/serial_core.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c > index 8f3dfc8b5307..fc677534b510 100644 > --- a/drivers/tty/serial/serial_core.c > +++ b/drivers/tty/serial/serial_core.c > @@ -1780,6 +1780,8 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i) > seq_printf(m, " brk:%d", uport->icount.brk); > if (uport->icount.overrun) > seq_printf(m, " oe:%d", uport->icount.overrun); > + if (uport->icount.buf_overrun) > + seq_printf(m, " bo:%d", uport->icount.buf_overrun); Hopefully this doesn't break any tools that might want to parse this file :)
On 03/20/2018 09:52 PM, Jeremy Kerr wrote: > The buf_overrun count is only every written, and not exposed to > userspace anywhere. This means that dropped characters due to flip > buffer overruns are never visible to userspace. > > The /proc/tty/driver/serial file exports a bunch of metrics (including > hardware overruns) already, so add the buf_overrun (as "bo:") to this > file. Tested-by: Eddie James <eajames@linux.vnet.ibm.com> > > Signed-off-by: Jeremy Kerr <jk@ozlabs.org> > --- > drivers/tty/serial/serial_core.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c > index 8f3dfc8b5307..fc677534b510 100644 > --- a/drivers/tty/serial/serial_core.c > +++ b/drivers/tty/serial/serial_core.c > @@ -1780,6 +1780,8 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i) > seq_printf(m, " brk:%d", uport->icount.brk); > if (uport->icount.overrun) > seq_printf(m, " oe:%d", uport->icount.overrun); > + if (uport->icount.buf_overrun) > + seq_printf(m, " bo:%d", uport->icount.buf_overrun); > > #define INFOBIT(bit, str) \ > if (uport->mctrl & (bit)) \
Hi Greg, >> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c >> index 8f3dfc8b5307..fc677534b510 100644 >> --- a/drivers/tty/serial/serial_core.c >> +++ b/drivers/tty/serial/serial_core.c >> @@ -1780,6 +1780,8 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i) >> seq_printf(m, " brk:%d", uport->icount.brk); >> if (uport->icount.overrun) >> seq_printf(m, " oe:%d", uport->icount.overrun); >> + if (uport->icount.buf_overrun) >> + seq_printf(m, " bo:%d", uport->icount.buf_overrun); > > Hopefully this doesn't break any tools that might want to parse this > file :) Given that those existing fe/pe/brk/oe fields only appear when they're non-zero, existing parsing code needs to be tolerant of different sets of fields being present/absent. Hopefully that means that a new field shouldn't be too much of a surprise? Otherwise, I'm happy to report the buf_overrun count elsewhere, if there's a more suitable place. Cheers, Jeremy
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 8f3dfc8b5307..fc677534b510 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1780,6 +1780,8 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i) seq_printf(m, " brk:%d", uport->icount.brk); if (uport->icount.overrun) seq_printf(m, " oe:%d", uport->icount.overrun); + if (uport->icount.buf_overrun) + seq_printf(m, " bo:%d", uport->icount.buf_overrun); #define INFOBIT(bit, str) \ if (uport->mctrl & (bit)) \
The buf_overrun count is only every written, and not exposed to userspace anywhere. This means that dropped characters due to flip buffer overruns are never visible to userspace. The /proc/tty/driver/serial file exports a bunch of metrics (including hardware overruns) already, so add the buf_overrun (as "bo:") to this file. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> --- drivers/tty/serial/serial_core.c | 2 ++ 1 file changed, 2 insertions(+)