| Message ID | 1366638237-6880-3-git-send-email-sourav.poddar@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On Mon, Apr 22, 2013 at 07:13:54PM +0530, Sourav Poddar wrote: > The driver manages "no_console_suspend" by preventing runtime PM > during the suspend path, which forces the console UART to stay awake. > > Signed-off-by: Sourav Poddar <sourav.poddar@ti.com> > --- > drivers/tty/serial/omap-serial.c | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c > index 08332f3..640b14e 100644 > --- a/drivers/tty/serial/omap-serial.c > +++ b/drivers/tty/serial/omap-serial.c > @@ -1582,7 +1582,7 @@ static int serial_omap_runtime_suspend(struct device *dev) > struct uart_omap_port *up = dev_get_drvdata(dev); > struct omap_uart_port_info *pdata = dev->platform_data; > > - if (!up) > + if (!up || (!console_suspend_enabled && uart_console(&up->port))) > return -EINVAL; -EBUSY would be a better value for uart_console case, so this check should be splitted accordingly. Likewise on second hunk.
On 04/22/2013 04:43 PM, Sourav Poddar wrote: > The driver manages "no_console_suspend" by preventing runtime PM > during the suspend path, which forces the console UART to stay awake. > > Signed-off-by: Sourav Poddar <sourav.poddar@ti.com> > --- > drivers/tty/serial/omap-serial.c | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c > index 08332f3..640b14e 100644 > --- a/drivers/tty/serial/omap-serial.c > +++ b/drivers/tty/serial/omap-serial.c > @@ -1582,7 +1582,7 @@ static int serial_omap_runtime_suspend(struct device *dev) > struct uart_omap_port *up = dev_get_drvdata(dev); > struct omap_uart_port_info *pdata = dev->platform_data; > > - if (!up) > + if (!up || (!console_suspend_enabled && uart_console(&up->port))) > return -EINVAL; Hi Sourav, No ) You will block Runtime PM for console UART forever, but instead it need to be blocked only during suspend - autosuspend should continue working. But this will be not easy, again, - because System suspend isn't synchronized with Runtime PM (I mean, serial_omap_suspend/resume() may be called from one thread and serial_omap_runtime_suspend/resume() from another at same time). And now, serial_omap_suspend() callback is the only one place where you can detect that system is going to sleep. Personally, i don't believe in such approach (my experiences from K3.4 said me that there will be more problems than benefits). And, I like combination of "no_console_suspend" in bootargs + "ti,no_idle_on_suspend" for console UART in DT, because 1) it's debug option and 2) until smth. will be decided about OMAP OCP Bus it can be used. It's just my opinion. Regards, -grygorii > > if (!pdata) > @@ -1614,6 +1614,9 @@ static int serial_omap_runtime_resume(struct device *dev) > > int loss_cnt = serial_omap_get_context_loss_count(up); > > + if (!console_suspend_enabled && uart_console(&up->port)) > + return -EINVAL; > + > if (loss_cnt < 0) { > dev_err(dev, "serial_omap_get_context_loss_count failed : %d\n", > loss_cnt); -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Grygorii Strashko <grygorii.strashko@ti.com> writes: > On 04/22/2013 04:43 PM, Sourav Poddar wrote: >> The driver manages "no_console_suspend" by preventing runtime PM >> during the suspend path, which forces the console UART to stay awake. >> >> Signed-off-by: Sourav Poddar <sourav.poddar@ti.com> >> --- >> drivers/tty/serial/omap-serial.c | 5 ++++- >> 1 files changed, 4 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c >> index 08332f3..640b14e 100644 >> --- a/drivers/tty/serial/omap-serial.c >> +++ b/drivers/tty/serial/omap-serial.c >> @@ -1582,7 +1582,7 @@ static int serial_omap_runtime_suspend(struct device *dev) >> struct uart_omap_port *up = dev_get_drvdata(dev); >> struct omap_uart_port_info *pdata = dev->platform_data; >> - if (!up) >> + if (!up || (!console_suspend_enabled && uart_console(&up->port))) >> return -EINVAL; > Hi Sourav, > No ) You will block Runtime PM for console UART forever, but instead > it need to be blocked only during suspend - autosuspend should > continue working. Correct. Sourav, as I mentioned when I suggested this approach, it should be done *only* during suspend. > But this will be not easy, again, - > because System suspend isn't synchronized with Runtime PM (I mean, > serial_omap_suspend/resume() may be called from one thread and > serial_omap_runtime_suspend/resume() from another at same time). > And now, serial_omap_suspend() callback is the only one place where you > can detect that system is going to sleep. So set an 'is_suspending' flag in ->suspend (it may need to be in ->prepare) and clear it in ->resume (->complete), and check the flag in the ->runtime_supend() callback. It's not uncommon for drivers to have such a flag for various reasons. > Personally, i don't believe in such approach (my experiences from K3.4 > said me that there will be more problems than benefits). > > And, I like combination of "no_console_suspend" in bootargs + > "ti,no_idle_on_suspend" for console UART in DT, because 1) it's debug > option and 2) until > smth. will be decided about OMAP OCP Bus it can be used. > > It's just my opinion. No, we need to get rid of ti,no_idle_on_suspend. It's an ugly, OMAP-specific hack (and I'm free to insult it because I introduced it.) Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Felipe, On Monday 22 April 2013 08:01 PM, Felipe Balbi wrote: > Hi, > > On Mon, Apr 22, 2013 at 07:13:54PM +0530, Sourav Poddar wrote: >> The driver manages "no_console_suspend" by preventing runtime PM >> during the suspend path, which forces the console UART to stay awake. >> >> Signed-off-by: Sourav Poddar<sourav.poddar@ti.com> >> --- >> drivers/tty/serial/omap-serial.c | 5 ++++- >> 1 files changed, 4 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c >> index 08332f3..640b14e 100644 >> --- a/drivers/tty/serial/omap-serial.c >> +++ b/drivers/tty/serial/omap-serial.c >> @@ -1582,7 +1582,7 @@ static int serial_omap_runtime_suspend(struct device *dev) >> struct uart_omap_port *up = dev_get_drvdata(dev); >> struct omap_uart_port_info *pdata = dev->platform_data; >> >> - if (!up) >> + if (!up || (!console_suspend_enabled&& uart_console(&up->port))) >> return -EINVAL; > -EBUSY would be a better value for uart_console case, so this check > should be splitted accordingly. Likewise on second hunk. > Ok. Will change in the next version. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Grygorii, On Monday 22 April 2013 08:18 PM, Grygorii Strashko wrote: > On 04/22/2013 04:43 PM, Sourav Poddar wrote: >> The driver manages "no_console_suspend" by preventing runtime PM >> during the suspend path, which forces the console UART to stay awake. >> >> Signed-off-by: Sourav Poddar <sourav.poddar@ti.com> >> --- >> drivers/tty/serial/omap-serial.c | 5 ++++- >> 1 files changed, 4 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/tty/serial/omap-serial.c >> b/drivers/tty/serial/omap-serial.c >> index 08332f3..640b14e 100644 >> --- a/drivers/tty/serial/omap-serial.c >> +++ b/drivers/tty/serial/omap-serial.c >> @@ -1582,7 +1582,7 @@ static int serial_omap_runtime_suspend(struct >> device *dev) >> struct uart_omap_port *up = dev_get_drvdata(dev); >> struct omap_uart_port_info *pdata = dev->platform_data; >> - if (!up) >> + if (!up || (!console_suspend_enabled && uart_console(&up->port))) >> return -EINVAL; > Hi Sourav, > No ) You will block Runtime PM for console UART forever, but instead > it need to be blocked only during suspend - autosuspend should > continue working. > But this will be not easy, again, - > because System suspend isn't synchronized with Runtime PM (I mean, > serial_omap_suspend/resume() may be called from one thread and > serial_omap_runtime_suspend/resume() from another at same time). > And now, serial_omap_suspend() callback is the only one place where you > can detect that system is going to sleep. > Yes, got this point. As Kevin has already suggested a way to get around this, I will fix this portion in the next version. > Personally, i don't believe in such approach (my experiences from K3.4 > said me > that there will be more problems than benefits). > > And, I like combination of "no_console_suspend" in bootargs + > "ti,no_idle_on_suspend" for console UART in DT, because 1) it's debug > option and 2) until > smth. will be decided about OMAP OCP Bus it can be used. > > It's just my opinion. > > Regards, > -grygorii >> if (!pdata) >> @@ -1614,6 +1614,9 @@ static int serial_omap_runtime_resume(struct >> device *dev) >> int loss_cnt = serial_omap_get_context_loss_count(up); >> + if (!console_suspend_enabled && uart_console(&up->port)) >> + return -EINVAL; >> + >> if (loss_cnt < 0) { >> dev_err(dev, "serial_omap_get_context_loss_count failed : >> %d\n", >> loss_cnt); > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Kevin, On Tuesday 23 April 2013 12:06 AM, Kevin Hilman wrote: > Grygorii Strashko<grygorii.strashko@ti.com> writes: > >> On 04/22/2013 04:43 PM, Sourav Poddar wrote: >>> The driver manages "no_console_suspend" by preventing runtime PM >>> during the suspend path, which forces the console UART to stay awake. >>> >>> Signed-off-by: Sourav Poddar<sourav.poddar@ti.com> >>> --- >>> drivers/tty/serial/omap-serial.c | 5 ++++- >>> 1 files changed, 4 insertions(+), 1 deletions(-) >>> >>> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c >>> index 08332f3..640b14e 100644 >>> --- a/drivers/tty/serial/omap-serial.c >>> +++ b/drivers/tty/serial/omap-serial.c >>> @@ -1582,7 +1582,7 @@ static int serial_omap_runtime_suspend(struct device *dev) >>> struct uart_omap_port *up = dev_get_drvdata(dev); >>> struct omap_uart_port_info *pdata = dev->platform_data; >>> - if (!up) >>> + if (!up || (!console_suspend_enabled&& uart_console(&up->port))) >>> return -EINVAL; >> Hi Sourav, >> No ) You will block Runtime PM for console UART forever, but instead >> it need to be blocked only during suspend - autosuspend should >> continue working. > Correct. > > Sourav, as I mentioned when I suggested this approach, it should be done > *only* during suspend. > Yes, got the point. >> But this will be not easy, again, - >> because System suspend isn't synchronized with Runtime PM (I mean, >> serial_omap_suspend/resume() may be called from one thread and >> serial_omap_runtime_suspend/resume() from another at same time). >> And now, serial_omap_suspend() callback is the only one place where you >> can detect that system is going to sleep. > So set an 'is_suspending' flag in ->suspend (it may need to be in > ->prepare) and clear it in ->resume (->complete), and check the flag in > the ->runtime_supend() callback. It's not uncommon for drivers to have > such a flag for various reasons. > Ok. Will adapt the next version inline with the above suggestions. >> Personally, i don't believe in such approach (my experiences from K3.4 >> said me that there will be more problems than benefits). >> >> And, I like combination of "no_console_suspend" in bootargs + >> "ti,no_idle_on_suspend" for console UART in DT, because 1) it's debug >> option and 2) until >> smth. will be decided about OMAP OCP Bus it can be used. >> >> It's just my opinion. > No, we need to get rid of ti,no_idle_on_suspend. It's an ugly, > OMAP-specific hack (and I'm free to insult it because I introduced it.) > > Kevin > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 08332f3..640b14e 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -1582,7 +1582,7 @@ static int serial_omap_runtime_suspend(struct device *dev) struct uart_omap_port *up = dev_get_drvdata(dev); struct omap_uart_port_info *pdata = dev->platform_data; - if (!up) + if (!up || (!console_suspend_enabled && uart_console(&up->port))) return -EINVAL; if (!pdata) @@ -1614,6 +1614,9 @@ static int serial_omap_runtime_resume(struct device *dev) int loss_cnt = serial_omap_get_context_loss_count(up); + if (!console_suspend_enabled && uart_console(&up->port)) + return -EINVAL; + if (loss_cnt < 0) { dev_err(dev, "serial_omap_get_context_loss_count failed : %d\n", loss_cnt);
The driver manages "no_console_suspend" by preventing runtime PM during the suspend path, which forces the console UART to stay awake. Signed-off-by: Sourav Poddar <sourav.poddar@ti.com> --- drivers/tty/serial/omap-serial.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-)