2018-10-15 20:45:34

by Doug Anderson

Subject: [PATCH] tty: serial: qcom_geni_serial: Don't slow all ports just for kgdb

If you turn on CONFIG_KGDB then you'll get CONFIG_CONSOLE_POLL
selected.

If you have CONFIG_CONSOLE_POLL selected then the GENI serial driver
was setting RX_BYTES_PW to 1 for _all_ UART ports.

This doesn't seem like such a good idea. Let's only set RX_BYTES_PW
to 1 for the console port.

Signed-off-by: Douglas Anderson <[email protected]>
---

drivers/tty/serial/qcom_geni_serial.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index d3b5261ee80a..9ee6ce725e43 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -89,9 +89,9 @@
#define MAX_LOOPBACK_CFG 3

#ifdef CONFIG_CONSOLE_POLL
-#define RX_BYTES_PW 1
+#define CONSOLE_RX_BYTES_PW 1
#else
-#define RX_BYTES_PW 4
+#define CONSOLE_RX_BYTES_PW 4
#endif

struct qcom_geni_serial_port {
@@ -853,11 +853,13 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport)
unsigned int rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT;
u32 proto;

- if (uart_console(uport))
+ if (uart_console(uport)) {
port->tx_bytes_pw = 1;
- else
+ port->rx_bytes_pw = CONSOLE_RX_BYTES_PW;
+ } else {
port->tx_bytes_pw = 4;
- port->rx_bytes_pw = RX_BYTES_PW;
+ port->rx_bytes_pw = 4;
+ }

proto = geni_se_read_proto(&port->se);
if (proto != GENI_SE_UART) {
--
2.19.1.331.ge82ca0e54c-goog

2018-10-16 20:54:14

by Stephen Boyd

Subject: Re: [PATCH] tty: serial: qcom_geni_serial: Don't slow all ports just for kgdb

Quoting Douglas Anderson (2018-10-15 13:44:24)
> If you turn on CONFIG_KGDB then you'll get CONFIG_CONSOLE_POLL
> selected.
>
> If you have CONFIG_CONSOLE_POLL selected then the GENI serial driver
> was setting RX_BYTES_PW to 1 for _all_ UART ports.
>
> This doesn't seem like such a good idea. Let's only set RX_BYTES_PW
> to 1 for the console port.
>
> Signed-off-by: Douglas Anderson <[email protected]>
> ---

Reviewed-by: Stephen Boyd <[email protected]>

2018-10-17 07:35:07

by Mukesh, Savaliya

Subject: Re: [PATCH] tty: serial: qcom_geni_serial: Don't slow all ports just for kgdb

On 2018-10-16 02:14, Douglas Anderson wrote:
> If you turn on CONFIG_KGDB then you'll get CONFIG_CONSOLE_POLL
> selected.
>
> If you have CONFIG_CONSOLE_POLL selected then the GENI serial driver
> was setting RX_BYTES_PW to 1 for _all_ UART ports.
>
> This doesn't seem like such a good idea. Let's only set RX_BYTES_PW
> to 1 for the console port.
>
> Signed-off-by: Douglas Anderson <[email protected]>
> ---
>
> drivers/tty/serial/qcom_geni_serial.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
Good finding, Makes sense to keep changes this way for console only
port.

Reviewed-by: Mukesh Kumar Savaliya <[email protected]>