Quoting Deepak Kumar Singh (2021-07-23 02:51:50) > > On 7/21/2021 12:07 PM, Stephen Boyd wrote: > > Quoting Sibi Sankar (2021-06-09 04:18:51) > >> From: Deepak Kumar Singh <deesin@xxxxxxxxxxxxxx> > >> > >> Not all upcoming usecases will have an interface to allow the aoss > >> driver to hook onto. Expose the send api and create a get function to > >> enable drivers to send their own messages to aoss. > >> > >> Signed-off-by: Chris Lew <clew@xxxxxxxxxxxxxx> > >> Signed-off-by: Deepak Kumar Singh <deesin@xxxxxxxxxxxxxx> > >> Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> > >> Signed-off-by: Sibi Sankar <sibis@xxxxxxxxxxxxxx> > >> --- > >> > >> v4: > >> * Fix compilation error due to missing qmp_put > >> * Minor typos [s/tarcks/tracks] > >> > >> drivers/soc/qcom/qcom_aoss.c | 70 ++++++++++++++++++++++++++++++++++++-- > >> include/linux/soc/qcom/qcom_aoss.h | 36 ++++++++++++++++++++ > >> 2 files changed, 104 insertions(+), 2 deletions(-) > >> create mode 100644 include/linux/soc/qcom/qcom_aoss.h > >> > >> diff --git a/drivers/soc/qcom/qcom_aoss.c b/drivers/soc/qcom/qcom_aoss.c > >> index 934fcc4d2b05..e8f48760bac8 100644 > >> --- a/drivers/soc/qcom/qcom_aoss.c > >> +++ b/drivers/soc/qcom/qcom_aoss.c > >> @@ -522,13 +582,14 @@ static int qmp_probe(struct platform_device *pdev) > >> int irq; > >> int ret; > >> > >> - qmp = devm_kzalloc(&pdev->dev, sizeof(*qmp), GFP_KERNEL); > >> + qmp = kzalloc(sizeof(*qmp), GFP_KERNEL); > >> if (!qmp) > >> return -ENOMEM; > >> > >> qmp->dev = &pdev->dev; > >> init_waitqueue_head(&qmp->event); > >> mutex_init(&qmp->tx_lock); > >> + kref_init(&qmp->refcount); > >> > >> res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > >> qmp->msgram = devm_ioremap_resource(&pdev->dev, res); > >> @@ -569,6 +630,8 @@ static int qmp_probe(struct platform_device *pdev) > >> > >> platform_set_drvdata(pdev, qmp); > >> > >> + atomic_set(&qmp->orphan, 0); > >> + > >> return 0; > >> > >> err_remove_qdss_clk: > >> @@ -577,6 +640,7 @@ static int qmp_probe(struct platform_device *pdev) > >> qmp_close(qmp); > >> err_free_mbox: > >> mbox_free_channel(qmp->mbox_chan); > >> + kfree(qmp); > >> > >> return ret; > >> } > >> @@ -590,7 +654,9 @@ static int qmp_remove(struct platform_device *pdev) > >> qmp_cooling_devices_remove(qmp); > >> > >> qmp_close(qmp); > >> + atomic_set(&qmp->orphan, 1); > > This looks odd. Why are we letting the device be removed while it is in > > use by other drivers? Can't we pin the device with get_device() so it > > can't be removed and then prevent the driver from being removed until > > all the consumer drivers drop the reference, i.e. suppress sysfs unbind? > > > > Otherwise it looks like a generic problem that all provider devices, > > clks, regulators, gpios, etc. have to deal with and thus this > > hand-rolled mechanism can't be right. > > As per my earlier discussion with Bjorn, device could be unbound using > sysfs, in which case > > remove() is called irrespective of whether any client driver is holding > struct device reference > > or not. That's why i have added separate refcount for qmp handle and > marking it invalid if > > qmp_remove() is called. > We have struct device_driver::suppress_bind_attrs for that. Can you set it?
