Re: [PATCH 1/3] Input: applespi: Don't wait for responses to commands indefinitely.

[Dmitry Torokhov]

On Wed, Feb 17, 2021 at 12:45:51PM -0800, Life is hard, and then you die wrote:
> 
>   Hi Dmitry,
> 
> On Wed, Feb 17, 2021 at 12:23:23PM -0800, Dmitry Torokhov wrote:
> > 
> > On Wed, Feb 17, 2021 at 11:07:16AM -0800, Ronald Tschalär wrote:
> > > @@ -869,7 +878,7 @@ static int applespi_send_cmd_msg(struct applespi_data 
> > > *applespi)
> > >   return sts;
> > >   }
> > >  
> > > - applespi->cmd_msg_queued = true;
> > > + applespi->cmd_msg_queued = ktime_get();
> > 
> > Will it be OK if I change this to ktime_get_coarse()? I do not think we
> > need exact time here, and the coarse variant is cheaper I believe.
> 
> Certainly - I just wasn't aware of the coarse variant.

Applied, thank you.

-- 
Dmitry

Re: [PATCH 1/3] Input: applespi: Don't wait for responses to commands indefinitely.

[Life is hard, and then you die]

  Hi Dmitry,

On Wed, Feb 17, 2021 at 12:23:23PM -0800, Dmitry Torokhov wrote:
> 
> On Wed, Feb 17, 2021 at 11:07:16AM -0800, Ronald Tschalär wrote:
> > @@ -869,7 +878,7 @@ static int applespi_send_cmd_msg(struct applespi_data 
> > *applespi)
> > return sts;
> > }
> >  
> > -   applespi->cmd_msg_queued = true;
> > +   applespi->cmd_msg_queued = ktime_get();
> 
> Will it be OK if I change this to ktime_get_coarse()? I do not think we
> need exact time here, and the coarse variant is cheaper I believe.

Certainly - I just wasn't aware of the coarse variant.


  Cheers,

  Ronald

Re: [PATCH 1/3] Input: applespi: Don't wait for responses to commands indefinitely.

[Dmitry Torokhov]

Hi Ronald,

On Wed, Feb 17, 2021 at 11:07:16AM -0800, Ronald Tschalär wrote:
> @@ -869,7 +878,7 @@ static int applespi_send_cmd_msg(struct applespi_data 
> *applespi)
>   return sts;
>   }
>  
> - applespi->cmd_msg_queued = true;
> + applespi->cmd_msg_queued = ktime_get();

Will it be OK if I change this to ktime_get_coarse()? I do not think we
need exact time here, and the coarse variant is cheaper I believe.

Thanks.

-- 
Dmitry

[PATCH 1/3] Input: applespi: Don't wait for responses to commands indefinitely.

[Ronald Tschalär]

The response to a command may never arrive or it may be corrupted (and
hence dropped) for some reason. While exceedingly rare, when it did
happen it blocked all further commands. One way to fix this was to
do a suspend/resume. However, recovering automatically seems like a
nicer option. Hence this puts a time limit (1 sec) on how long we're
willing to wait for a response, after which we assume it got lost.

Signed-off-by: Ronald Tschalär 
---
 drivers/input/keyboard/applespi.c | 21 +++--
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/input/keyboard/applespi.c 
b/drivers/input/keyboard/applespi.c
index d3154177f..8494bf610fd70 100644
--- a/drivers/input/keyboard/applespi.c
+++ b/drivers/input/keyboard/applespi.c
@@ -48,6 +48,7 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -409,7 +410,7 @@ struct applespi_data {
unsigned intcmd_msg_cntr;
/* lock to protect the above parameters and flags below */
spinlock_t  cmd_msg_lock;
-   boolcmd_msg_queued;
+   ktime_t cmd_msg_queued;
enum applespi_evt_type  cmd_evt_type;
 
struct led_classdev backlight_info;
@@ -729,7 +730,7 @@ static void applespi_msg_complete(struct applespi_data 
*applespi,
wake_up_all(&applespi->drain_complete);
 
if (is_write_msg) {
-   applespi->cmd_msg_queued = false;
+   applespi->cmd_msg_queued = 0;
applespi_send_cmd_msg(applespi);
}
 
@@ -771,8 +772,16 @@ static int applespi_send_cmd_msg(struct applespi_data 
*applespi)
return 0;
 
/* check whether send is in progress */
-   if (applespi->cmd_msg_queued)
-   return 0;
+   if (applespi->cmd_msg_queued) {
+   if (ktime_ms_delta(ktime_get(), applespi->cmd_msg_queued) < 
1000)
+   return 0;
+
+   dev_warn(&applespi->spi->dev, "Command %d timed out\n",
+applespi->cmd_evt_type);
+
+   applespi->cmd_msg_queued = 0;
+   applespi->write_active = false;
+   }
 
/* set up packet */
memset(packet, 0, APPLESPI_PACKET_SIZE);
@@ -869,7 +878,7 @@ static int applespi_send_cmd_msg(struct applespi_data 
*applespi)
return sts;
}
 
-   applespi->cmd_msg_queued = true;
+   applespi->cmd_msg_queued = ktime_get();
applespi->write_active = true;
 
return 0;
@@ -1921,7 +1930,7 @@ static int __maybe_unused applespi_resume(struct device 
*dev)
applespi->drain = false;
applespi->have_cl_led_on = false;
applespi->have_bl_level = 0;
-   applespi->cmd_msg_queued = false;
+   applespi->cmd_msg_queued = 0;
applespi->read_active = false;
applespi->write_active = false;
 
-- 
2.26.2