| Message ID | 1360862257-10807-1-git-send-email-hechtb+renesas@gmail.com |
|---|---|
| State | Changes Requested |
| Headers | show |
On Thu, Feb 14, 2013 at 11:17:37AM -0600, Bastian Hecht wrote: > Currently we provoke i2c timeouts by allowing transfers when > suspending. This patch adds awareness to suspending and fixes these > issues. > The patch follows the style used in i2c-tegra.c - thanks. Hi, at this stage I do not expect this code to go through the renesas tree. However, in order to provide a basis for work on renesas SoCs I have added this patch to the topic/i2c topic branch in the reneas tree on kernel.org and merged it into topic/all+next. In other words, I am not picking this patch up to merge it or add it to linux-next, rather I am storing it for reference. > > Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com> > --- > drivers/i2c/busses/i2c-sh_mobile.c | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c > index b6e7a83..da28164 100644 > --- a/drivers/i2c/busses/i2c-sh_mobile.c > +++ b/drivers/i2c/busses/i2c-sh_mobile.c > @@ -132,6 +132,7 @@ struct sh_mobile_i2c_data { > struct i2c_msg *msg; > int pos; > int sr; > + bool is_suspended; > }; > > #define IIC_FLAG_HAS_ICIC67 (1 << 0) > @@ -511,6 +512,9 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter, > u_int8_t val; > int i, k, retry_count; > > + if (pd->is_suspended) > + return -EBUSY; > + > activate_ch(pd); > > /* Process all messages */ > @@ -753,9 +757,33 @@ static int sh_mobile_i2c_runtime_nop(struct device *dev) > return 0; > } > > +static int sh_mobile_i2c_suspend(struct device *dev) > +{ > + struct sh_mobile_i2c_data *pd = dev_get_drvdata(dev); > + > + i2c_lock_adapter(&pd->adap); > + pd->is_suspended = true; > + i2c_unlock_adapter(&pd->adap); > + > + return 0; > +} > + > +static int sh_mobile_i2c_resume(struct device *dev) > +{ > + struct sh_mobile_i2c_data *pd = dev_get_drvdata(dev); > + > + i2c_lock_adapter(&pd->adap); > + pd->is_suspended = false; > + i2c_unlock_adapter(&pd->adap); > + > + return 0; > +} > + > static const struct dev_pm_ops sh_mobile_i2c_dev_pm_ops = { > .runtime_suspend = sh_mobile_i2c_runtime_nop, > .runtime_resume = sh_mobile_i2c_runtime_nop, > + .suspend = sh_mobile_i2c_suspend, > + .resume = sh_mobile_i2c_resume, > }; > > static const struct of_device_id sh_mobile_i2c_dt_ids[] = { > -- > 1.7.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sh" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Feb 15, 2013 at 2:17 AM, Bastian Hecht <hechtb@gmail.com> wrote: > Currently we provoke i2c timeouts by allowing transfers when > suspending. This patch adds awareness to suspending and fixes these > issues. > The patch follows the style used in i2c-tegra.c - thanks. > > Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com> > --- > drivers/i2c/busses/i2c-sh_mobile.c | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c > index b6e7a83..da28164 100644 > --- a/drivers/i2c/busses/i2c-sh_mobile.c > +++ b/drivers/i2c/busses/i2c-sh_mobile.c > @@ -132,6 +132,7 @@ struct sh_mobile_i2c_data { > struct i2c_msg *msg; > int pos; > int sr; > + bool is_suspended; > }; > > #define IIC_FLAG_HAS_ICIC67 (1 << 0) > @@ -511,6 +512,9 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter, > u_int8_t val; > int i, k, retry_count; > > + if (pd->is_suspended) > + return -EBUSY; > + > activate_ch(pd); > > /* Process all messages */ > @@ -753,9 +757,33 @@ static int sh_mobile_i2c_runtime_nop(struct device *dev) > return 0; > } > > +static int sh_mobile_i2c_suspend(struct device *dev) > +{ > + struct sh_mobile_i2c_data *pd = dev_get_drvdata(dev); > + > + i2c_lock_adapter(&pd->adap); > + pd->is_suspended = true; > + i2c_unlock_adapter(&pd->adap); > + > + return 0; > +} > + > +static int sh_mobile_i2c_resume(struct device *dev) > +{ > + struct sh_mobile_i2c_data *pd = dev_get_drvdata(dev); > + > + i2c_lock_adapter(&pd->adap); > + pd->is_suspended = false; > + i2c_unlock_adapter(&pd->adap); > + > + return 0; > +} > + > static const struct dev_pm_ops sh_mobile_i2c_dev_pm_ops = { > .runtime_suspend = sh_mobile_i2c_runtime_nop, > .runtime_resume = sh_mobile_i2c_runtime_nop, > + .suspend = sh_mobile_i2c_suspend, > + .resume = sh_mobile_i2c_resume, > }; > > static const struct of_device_id sh_mobile_i2c_dt_ids[] = { > -- Hi Bastian, Thanks for your work on this. Can you tell us a bit more about where and when this fix is needed? I am guessing here, but perhaps it only triggers on SMP hardware with CONFIG_SMP enabled? Also, do you know the reason why this isn't handled in the i2c layer by default? I ask because your comment mentions that i2c-tegra.c does the same thing and I can't see anything in this patch that is actually related to our I2C hardware. Thanks, / magnus -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2013/2/15 Magnus Damm <magnus.damm@gmail.com>: > On Fri, Feb 15, 2013 at 2:17 AM, Bastian Hecht <hechtb@gmail.com> wrote: >> Currently we provoke i2c timeouts by allowing transfers when >> suspending. This patch adds awareness to suspending and fixes these >> issues. >> The patch follows the style used in i2c-tegra.c - thanks. >> >> Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com> >> --- >> drivers/i2c/busses/i2c-sh_mobile.c | 28 ++++++++++++++++++++++++++++ >> 1 file changed, 28 insertions(+) >> >> diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c >> index b6e7a83..da28164 100644 >> --- a/drivers/i2c/busses/i2c-sh_mobile.c >> +++ b/drivers/i2c/busses/i2c-sh_mobile.c >> @@ -132,6 +132,7 @@ struct sh_mobile_i2c_data { >> struct i2c_msg *msg; >> int pos; >> int sr; >> + bool is_suspended; >> }; >> >> #define IIC_FLAG_HAS_ICIC67 (1 << 0) >> @@ -511,6 +512,9 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter, >> u_int8_t val; >> int i, k, retry_count; >> >> + if (pd->is_suspended) >> + return -EBUSY; >> + >> activate_ch(pd); >> >> /* Process all messages */ >> @@ -753,9 +757,33 @@ static int sh_mobile_i2c_runtime_nop(struct device *dev) >> return 0; >> } >> >> +static int sh_mobile_i2c_suspend(struct device *dev) >> +{ >> + struct sh_mobile_i2c_data *pd = dev_get_drvdata(dev); >> + >> + i2c_lock_adapter(&pd->adap); >> + pd->is_suspended = true; >> + i2c_unlock_adapter(&pd->adap); >> + >> + return 0; >> +} >> + >> +static int sh_mobile_i2c_resume(struct device *dev) >> +{ >> + struct sh_mobile_i2c_data *pd = dev_get_drvdata(dev); >> + >> + i2c_lock_adapter(&pd->adap); >> + pd->is_suspended = false; >> + i2c_unlock_adapter(&pd->adap); >> + >> + return 0; >> +} >> + >> static const struct dev_pm_ops sh_mobile_i2c_dev_pm_ops = { >> .runtime_suspend = sh_mobile_i2c_runtime_nop, >> .runtime_resume = sh_mobile_i2c_runtime_nop, >> + .suspend = sh_mobile_i2c_suspend, >> + .resume = sh_mobile_i2c_resume, >> }; >> >> static const struct of_device_id sh_mobile_i2c_dt_ids[] = { >> -- > > Hi Bastian, > > Thanks for your work on this. Can you tell us a bit more about where > and when this fix is needed? I am guessing here, but perhaps it only > triggers on SMP hardware with CONFIG_SMP enabled? It appears on the UP r8a7740 on my Armadillo. I didn't succeed in quickly triggering it on the sh73a0. > Also, do you know the reason why this isn't handled in the i2c layer > by default? I ask because your comment mentions that i2c-tegra.c does > the same thing and I can't see anything in this patch that is actually > related to our I2C hardware. Yes, many drivers have a similar scheme and to me it more looked like all drivers need to take care about this case unrelated to different hardware. So the question arises if this can't be handled in the core - or if I get something wrong here. I can have a deeper look later at this when the issues in "[PATCH] input: st1232: Add IRQF_NO_SUSPEND flag" become more clear and we can work on it without side effects of other bugs. So I suppose we should stall this patch until then. Thanks, Bastian > Thanks, > > / magnus -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Bastian, > > Also, do you know the reason why this isn't handled in the i2c layer > > by default? I ask because your comment mentions that i2c-tegra.c does > > the same thing and I can't see anything in this patch that is actually > > related to our I2C hardware. > > Yes, many drivers have a similar scheme and to me it more looked like > all drivers need to take care about this case unrelated to different > hardware. So the question arises if this can't be handled in the core > - or if I get something wrong here. I don't see any reason why this couldn't be handled in the core. If you want to have a take on this issue (after the other bug is fixed), this will be highly appreciated. Thanks, Wolfram -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Wolfram, oh yes I can gladly do so. To make a realistic estimation it might take a few weeks until I find time for it though. If we can wait so long, count on me. Best, Bastian 2013/2/21 Wolfram Sang <wsa@the-dreams.de>: > Hi Bastian, > >> > Also, do you know the reason why this isn't handled in the i2c layer >> > by default? I ask because your comment mentions that i2c-tegra.c does >> > the same thing and I can't see anything in this patch that is actually >> > related to our I2C hardware. >> >> Yes, many drivers have a similar scheme and to me it more looked like >> all drivers need to take care about this case unrelated to different >> hardware. So the question arises if this can't be handled in the core >> - or if I get something wrong here. > > I don't see any reason why this couldn't be handled in the core. If you > want to have a take on this issue (after the other bug is fixed), this > will be highly appreciated. > > Thanks, > > Wolfram > -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> oh yes I can gladly do so. To make a realistic estimation it might > take a few weeks until I find time for it though. If we can wait so > long, count on me. Totally fine with me. -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Feb 21, 2013 at 08:54:06AM -0600, Bastian Hecht wrote: > Hi Wolfram, > > oh yes I can gladly do so. To make a realistic estimation it might > take a few weeks until I find time for it though. If we can wait so > long, count on me. Ping. Still interested? > > Best, > > Bastian > > 2013/2/21 Wolfram Sang <wsa@the-dreams.de>: > > Hi Bastian, > > > >> > Also, do you know the reason why this isn't handled in the i2c layer > >> > by default? I ask because your comment mentions that i2c-tegra.c does > >> > the same thing and I can't see anything in this patch that is actually > >> > related to our I2C hardware. > >> > >> Yes, many drivers have a similar scheme and to me it more looked like > >> all drivers need to take care about this case unrelated to different > >> hardware. So the question arises if this can't be handled in the core > >> - or if I get something wrong here. > > > > I don't see any reason why this couldn't be handled in the core. If you > > want to have a take on this issue (after the other bug is fixed), this > > will be highly appreciated. > > > > Thanks, > > > > Wolfram > >
Just a quick note - will start next week on it. Cheers, Bastian 2014-05-21 13:00 GMT+02:00 Wolfram Sang <wsa@the-dreams.de>: > On Thu, Feb 21, 2013 at 08:54:06AM -0600, Bastian Hecht wrote: >> Hi Wolfram, >> >> oh yes I can gladly do so. To make a realistic estimation it might >> take a few weeks until I find time for it though. If we can wait so >> long, count on me. > > Ping. Still interested? > >> >> Best, >> >> Bastian >> >> 2013/2/21 Wolfram Sang <wsa@the-dreams.de>: >> > Hi Bastian, >> > >> >> > Also, do you know the reason why this isn't handled in the i2c layer >> >> > by default? I ask because your comment mentions that i2c-tegra.c does >> >> > the same thing and I can't see anything in this patch that is actually >> >> > related to our I2C hardware. >> >> >> >> Yes, many drivers have a similar scheme and to me it more looked like >> >> all drivers need to take care about this case unrelated to different >> >> hardware. So the question arises if this can't be handled in the core >> >> - or if I get something wrong here. >> > >> > I don't see any reason why this couldn't be handled in the core. If you >> > want to have a take on this issue (after the other bug is fixed), this >> > will be highly appreciated. >> > >> > Thanks, >> > >> > Wolfram >> > -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" 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/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index b6e7a83..da28164 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -132,6 +132,7 @@ struct sh_mobile_i2c_data { struct i2c_msg *msg; int pos; int sr; + bool is_suspended; }; #define IIC_FLAG_HAS_ICIC67 (1 << 0) @@ -511,6 +512,9 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter, u_int8_t val; int i, k, retry_count; + if (pd->is_suspended) + return -EBUSY; + activate_ch(pd); /* Process all messages */ @@ -753,9 +757,33 @@ static int sh_mobile_i2c_runtime_nop(struct device *dev) return 0; } +static int sh_mobile_i2c_suspend(struct device *dev) +{ + struct sh_mobile_i2c_data *pd = dev_get_drvdata(dev); + + i2c_lock_adapter(&pd->adap); + pd->is_suspended = true; + i2c_unlock_adapter(&pd->adap); + + return 0; +} + +static int sh_mobile_i2c_resume(struct device *dev) +{ + struct sh_mobile_i2c_data *pd = dev_get_drvdata(dev); + + i2c_lock_adapter(&pd->adap); + pd->is_suspended = false; + i2c_unlock_adapter(&pd->adap); + + return 0; +} + static const struct dev_pm_ops sh_mobile_i2c_dev_pm_ops = { .runtime_suspend = sh_mobile_i2c_runtime_nop, .runtime_resume = sh_mobile_i2c_runtime_nop, + .suspend = sh_mobile_i2c_suspend, + .resume = sh_mobile_i2c_resume, }; static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
Currently we provoke i2c timeouts by allowing transfers when suspending. This patch adds awareness to suspending and fixes these issues. The patch follows the style used in i2c-tegra.c - thanks. Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com> --- drivers/i2c/busses/i2c-sh_mobile.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)