Introduce mhi_get_free_desc_count() API to return number
of TREs available to queue buffer. MHI clients can use this
API to know before hand if ring is full without calling queue
API.
Signed-off-by: Hemant Kumar <[email protected]>
Reviewed-by: Jeffrey Hugo <[email protected]>
Reviewed-by: Manivannan Sadhasivam <[email protected]>
---
drivers/bus/mhi/core/main.c | 12 ++++++++++++
include/linux/mhi.h | 9 +++++++++
2 files changed, 21 insertions(+)
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index f953e2a..6158720 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -260,6 +260,18 @@ int mhi_destroy_device(struct device *dev, void *data)
return 0;
}
+int mhi_get_free_desc_count(struct mhi_device *mhi_dev,
+ enum dma_data_direction dir)
+{
+ struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+ struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ?
+ mhi_dev->ul_chan : mhi_dev->dl_chan;
+ struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
+
+ return get_nr_avail_ring_elements(mhi_cntrl, tre_ring);
+}
+EXPORT_SYMBOL_GPL(mhi_get_free_desc_count);
+
void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason)
{
struct mhi_driver *mhi_drv;
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 52b3c60..a4d0f48 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -597,6 +597,15 @@ void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl,
void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason);
/**
+ * mhi_get_free_desc_count - Get transfer ring length
+ * Get # of TD available to queue buffers
+ * @mhi_dev: Device associated with the channels
+ * @dir: Direction of the channel
+ */
+int mhi_get_free_desc_count(struct mhi_device *mhi_dev,
+ enum dma_data_direction dir);
+
+/**
* mhi_prepare_for_power_up - Do pre-initialization before power up.
* This is optional, call this before power up if
* the controller does not want bus framework to
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
On Mon, 16 Nov 2020 at 23:46, Hemant Kumar <[email protected]> wrote:
>
> Introduce mhi_get_free_desc_count() API to return number
> of TREs available to queue buffer. MHI clients can use this
> API to know before hand if ring is full without calling queue
> API.
>
> Signed-off-by: Hemant Kumar <[email protected]>
> Reviewed-by: Jeffrey Hugo <[email protected]>
> Reviewed-by: Manivannan Sadhasivam <[email protected]>
In case this series get new comments to address, I would suggest
merging that patch in mhi-next separately so that other drivers can
start benefiting this function (I would like to use it in mhi-net).
Regards,
Loic
On Sat, Nov 28, 2020 at 11:59:46AM +0530, Manivannan Sadhasivam wrote:
> On Wed, Nov 18, 2020 at 10:32:45AM +0100, Loic Poulain wrote:
> > On Mon, 16 Nov 2020 at 23:46, Hemant Kumar <[email protected]> wrote:
> > >
> > > Introduce mhi_get_free_desc_count() API to return number
> > > of TREs available to queue buffer. MHI clients can use this
> > > API to know before hand if ring is full without calling queue
> > > API.
> > >
> > > Signed-off-by: Hemant Kumar <[email protected]>
> > > Reviewed-by: Jeffrey Hugo <[email protected]>
> > > Reviewed-by: Manivannan Sadhasivam <[email protected]>
> >
> > In case this series get new comments to address, I would suggest
> > merging that patch in mhi-next separately so that other drivers can
> > start benefiting this function (I would like to use it in mhi-net).
> >
>
> Greg doesn't like that. He asked me to pick APIs only when there an in-tree
> consumer available.
If someone wants to use it, then yes, by all means merge it. I can't
just take new apis without any user.
thanks,
greg k-h
On Wed, Nov 18, 2020 at 10:32:45AM +0100, Loic Poulain wrote:
> On Mon, 16 Nov 2020 at 23:46, Hemant Kumar <[email protected]> wrote:
> >
> > Introduce mhi_get_free_desc_count() API to return number
> > of TREs available to queue buffer. MHI clients can use this
> > API to know before hand if ring is full without calling queue
> > API.
> >
> > Signed-off-by: Hemant Kumar <[email protected]>
> > Reviewed-by: Jeffrey Hugo <[email protected]>
> > Reviewed-by: Manivannan Sadhasivam <[email protected]>
>
> In case this series get new comments to address, I would suggest
> merging that patch in mhi-next separately so that other drivers can
> start benefiting this function (I would like to use it in mhi-net).
>
Greg doesn't like that. He asked me to pick APIs only when there an in-tree
consumer available.
Thanks,
Mani
> Regards,
> Loic