| Message ID | 1412028051-21774-1-git-send-email-agross@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Sep 29, 2014 at 05:00:51PM -0500, Andy Gross wrote: > The runtime pm calls need to be done before populating the children via the > i2c_add_adapter call. If this is not done, a child can run into issues trying > to do i2c read/writes due to the pm_runtime_sync failing. > > Signed-off-by: Andy Gross <agross@codeaurora.org> Reviewed-by: Felipe Balbi <balbi@ti.com>
On Mon 29 Sep 15:00 PDT 2014, Andy Gross wrote: > The runtime pm calls need to be done before populating the children via the > i2c_add_adapter call. If this is not done, a child can run into issues trying > to do i2c read/writes due to the pm_runtime_sync failing. > May I ask in what case this would fail? I thought we tested this as we found the faulty error check after calling pm_runtime_get_sync(). Nontheless, Acked-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> Regards, Bjorn > Signed-off-by: Andy Gross <agross@codeaurora.org> > --- > drivers/i2c/busses/i2c-qup.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c > index 3a4d64e..092d89b 100644 > --- a/drivers/i2c/busses/i2c-qup.c > +++ b/drivers/i2c/busses/i2c-qup.c > @@ -674,16 +674,20 @@ static int qup_i2c_probe(struct platform_device *pdev) > qup->adap.dev.of_node = pdev->dev.of_node; > strlcpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name)); > > - ret = i2c_add_adapter(&qup->adap); > - if (ret) > - goto fail; > - > pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC); > pm_runtime_use_autosuspend(qup->dev); > pm_runtime_set_active(qup->dev); > pm_runtime_enable(qup->dev); > + > + ret = i2c_add_adapter(&qup->adap); > + if (ret) > + goto fail_runtime; > + > return 0; > > +fail_runtime: > + pm_runtime_disable(qup->dev); > + pm_runtime_set_suspended(qup->dev); > fail: > qup_i2c_disable_clocks(qup); > return ret; > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > hosted by The Linux Foundation >
On Mon, Sep 29, 2014 at 06:53:24PM -0700, Bjorn Andersson wrote: > On Mon 29 Sep 15:00 PDT 2014, Andy Gross wrote: > > > The runtime pm calls need to be done before populating the children via the > > i2c_add_adapter call. If this is not done, a child can run into issues trying > > to do i2c read/writes due to the pm_runtime_sync failing. > > > > May I ask in what case this would fail? I thought we tested this as we found > the faulty error check after calling pm_runtime_get_sync(). This is a different kind of failure. If during probe, the children do some I2C activity, they will encounter issues with the runtime_sync due to the pm_runtime not being initialized. However, once the qup probe completes, everything works fine. The original runtime_sync issue revolved around the runtime_sync return value being misinterpreted due to the incorrect check. <snip>
On Tue 30 Sep 12:59 PDT 2014, Andy Gross wrote: > On Mon, Sep 29, 2014 at 06:53:24PM -0700, Bjorn Andersson wrote: > > On Mon 29 Sep 15:00 PDT 2014, Andy Gross wrote: > > > > > The runtime pm calls need to be done before populating the children via the > > > i2c_add_adapter call. If this is not done, a child can run into issues trying > > > to do i2c read/writes due to the pm_runtime_sync failing. > > > > > > > May I ask in what case this would fail? I thought we tested this as we found > > the faulty error check after calling pm_runtime_get_sync(). > > This is a different kind of failure. If during probe, the children do some I2C > activity, they will encounter issues with the runtime_sync due to the pm_runtime > not being initialized. However, once the qup probe completes, everything works > fine. > > The original runtime_sync issue revolved around the runtime_sync return value > being misinterpreted due to the incorrect check. > Yeah, I just wondered why my testing didn't trigger this. But I suspect that the answer is simply that the client I ran with did not do i2c accesses from probe. Regards, Bjorn
On Mon, Sep 29, 2014 at 05:00:51PM -0500, Andy Gross wrote: > The runtime pm calls need to be done before populating the children via the > i2c_add_adapter call. If this is not done, a child can run into issues trying > to do i2c read/writes due to the pm_runtime_sync failing. > > Signed-off-by: Andy Gross <agross@codeaurora.org> Applied to for-current, thanks!
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c index 3a4d64e..092d89b 100644 --- a/drivers/i2c/busses/i2c-qup.c +++ b/drivers/i2c/busses/i2c-qup.c @@ -674,16 +674,20 @@ static int qup_i2c_probe(struct platform_device *pdev) qup->adap.dev.of_node = pdev->dev.of_node; strlcpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name)); - ret = i2c_add_adapter(&qup->adap); - if (ret) - goto fail; - pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC); pm_runtime_use_autosuspend(qup->dev); pm_runtime_set_active(qup->dev); pm_runtime_enable(qup->dev); + + ret = i2c_add_adapter(&qup->adap); + if (ret) + goto fail_runtime; + return 0; +fail_runtime: + pm_runtime_disable(qup->dev); + pm_runtime_set_suspended(qup->dev); fail: qup_i2c_disable_clocks(qup); return ret;
The runtime pm calls need to be done before populating the children via the i2c_add_adapter call. If this is not done, a child can run into issues trying to do i2c read/writes due to the pm_runtime_sync failing. Signed-off-by: Andy Gross <agross@codeaurora.org> --- drivers/i2c/busses/i2c-qup.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)