[PATCH net v2 1/1] net: wwan: mhi_wwan_mbim: use correct mux_id for multiplexing

[Daniele Palmas <dnlplm@gmail.com>]

Recent Qualcomm chipsets like SDX72/75 require MBIM sessionId mapping
to muxId in the range (0x70-0x8F) for the PCIe tethered use.

This has been partially addressed by the referenced commit, mapping
the default data call to muxId = 112, but the multiplexed data calls
scenario was not properly considered, mapping sessionId = 1 to muxId
1, while it should have been 113.

Fix this by moving the session_id assignment logic to mhi_mbim_newlink,
in order to map sessionId = n to muxId = n + WDS_BIND_MUX_DATA_PORT_MUX_ID.

Fixes: 65bc58c3dcad ("net: wwan: mhi: make default data link id configurable")
Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
---
v2: change commit description including information from QC case according to
Loic's feedback

@Loic, I've left out the mux-id macro/function renaming, since I'm not sure
that it can really be considered a fix for net. Maybe we can think about it
when net-next opens again.

 drivers/net/wwan/mhi_wwan_mbim.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wwan/mhi_wwan_mbim.c b/drivers/net/wwan/mhi_wwan_mbim.c
index 8755c5e6a65b..c814fbd756a1 100644
--- a/drivers/net/wwan/mhi_wwan_mbim.c
+++ b/drivers/net/wwan/mhi_wwan_mbim.c
@@ -550,8 +550,8 @@ static int mhi_mbim_newlink(void *ctxt, struct net_device *ndev, u32 if_id,
 	struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
 	struct mhi_mbim_context *mbim = ctxt;
 
-	link->session = if_id;
 	link->mbim = mbim;
+	link->session = mhi_mbim_get_link_mux_id(link->mbim->mdev->mhi_cntrl) + if_id;
 	link->ndev = ndev;
 	u64_stats_init(&link->rx_syncp);
 	u64_stats_init(&link->tx_syncp);
@@ -607,7 +607,7 @@ static int mhi_mbim_probe(struct mhi_device *mhi_dev, const struct mhi_device_id
 {
 	struct mhi_controller *cntrl = mhi_dev->mhi_cntrl;
 	struct mhi_mbim_context *mbim;
-	int err, link_id;
+	int err;
 
 	mbim = devm_kzalloc(&mhi_dev->dev, sizeof(*mbim), GFP_KERNEL);
 	if (!mbim)
@@ -628,11 +628,8 @@ static int mhi_mbim_probe(struct mhi_device *mhi_dev, const struct mhi_device_id
 	/* Number of transfer descriptors determines size of the queue */
 	mbim->rx_queue_sz = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE);
 
-	/* Get the corresponding mux_id from mhi */
-	link_id = mhi_mbim_get_link_mux_id(cntrl);
-
 	/* Register wwan link ops with MHI controller representing WWAN instance */
-	return wwan_register_ops(&cntrl->mhi_dev->dev, &mhi_mbim_wwan_ops, mbim, link_id);
+	return wwan_register_ops(&cntrl->mhi_dev->dev, &mhi_mbim_wwan_ops, mbim, 0);
 }
 
 static void mhi_mbim_remove(struct mhi_device *mhi_dev)

base-commit: 408da3a0f89d581421ca9bd6ff39c7dd05bc4b2f
-- 
2.37.1