On 11/11/2023 1:14 AM, Jeffrey Hugo wrote:
On 11/10/2023 3:21 AM, Kalle Valo wrote:
From: Baochen Qiang <quic_bqiang@xxxxxxxxxxx>
When using mhi_power_down_no_destroy() MHI hosts need to unprepare
MHI channels
by themselves. Similarly, MHI stack will also not create new MHI
device since
old devices were not destroyed, so MHI hosts need to prepare channels
as well.
Hence add these two interfaces to make that possible.
Tested-on: WCN6855 hw2.0 PCI
WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.30
Signed-off-by: Baochen Qiang <quic_bqiang@xxxxxxxxxxx>
Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>
---
drivers/bus/mhi/host/main.c | 91 +++++++++++++++++++++++++++++++++++++
include/linux/mhi.h | 18 ++++++++
2 files changed, 109 insertions(+)
diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
index dcf627b36e82..9bcf8a49c000 100644
--- a/drivers/bus/mhi/host/main.c
+++ b/drivers/bus/mhi/host/main.c
@@ -1667,6 +1667,49 @@ int mhi_prepare_for_transfer_autoqueue(struct
mhi_device *mhi_dev)
}
EXPORT_SYMBOL_GPL(mhi_prepare_for_transfer_autoqueue);
+static int __mhi_prepare_for_transfer_autoqueue(struct device
*dev, void *data)
+{
+ struct mhi_device *mhi_dev;
+ struct mhi_chan *ul_chan, *dl_chan;
+ enum mhi_ee_type ee = MHI_EE_MAX;
+
+ if (dev->bus != &mhi_bus_type)
+ return 0;
+
+ mhi_dev = to_mhi_device(dev);
+
+ /* Only prepare virtual devices thats attached to bus */
"that are"?
It means MHI devices with a type of MHI_DEVICE_XFER. See also
mhi_destroy_device();
+ if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
+ return 0;
+
+ ul_chan = mhi_dev->ul_chan;
+ dl_chan = mhi_dev->dl_chan;
+
+ /*
+ * If execution environment is specified, remove only those
devices that
+ * started in them based on ee_mask for the channels as we move
on to a
+ * different execution environment
+ */
+ if (data)
+ ee = *(enum mhi_ee_type *)data;
+
+ if (ul_chan && ee != MHI_EE_MAX && !(ul_chan->ee_mask & BIT(ee)))
+ return 0;
+
+
+ if (dl_chan && ee != MHI_EE_MAX && !(dl_chan->ee_mask & BIT(ee)))
+ return 0;
+
+ return mhi_prepare_for_transfer_autoqueue(mhi_dev);
+}
+
+int mhi_prepare_all_for_transfer_autoqueue(struct mhi_controller
*mhi_cntrl)
+{
+ return device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL,
+ __mhi_prepare_for_transfer_autoqueue);
+}
+EXPORT_SYMBOL_GPL(mhi_prepare_all_for_transfer_autoqueue);
This seems broken. It appears to configure all channels as autoqueue,
regardless of how the controller initially configured them. This
would only be safe to use if all channels were configured for
autoqueue, but would silently cause issues otherwise.
Thanks for pointing that. Yes, it is not correct to treat all channels
as autoqueue regardless of its initial configuration. So how about
change as below:
/* The difference between mhi_prepare_for_transfer_autoqueue() and
mhi_prepare_for_transfer() comes from how to treat downlink channel */
mhi_prepare_for_transfer_dev(struct device *dev, ...)
{
...
dl_chan = mhi_dev->dl_chan;
...
if (dl_chan->pre_alloc)
mhi_prepare_for_transfer_autoqueue(dev);
else
mhi_prepare_for_transfer(dev);
}
/* And then iterate all devices and call mhi_prepare_for_transfer_dev()
for each. */
int mhi_prepare_all_for_transfer(struct mhi_controller *mhi_cntrl)
{
return device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL,
mhi_prepare_for_transfer_dev);
}
EXPORT_SYMBOL_GPL(mhi_prepare_all_for_transfer);
