Messages in this thread | | | Date | Wed, 21 Jul 2021 10:52:30 -0700 | From | hemantk@codeauro ... | Subject | Re: [PATCH] net: qrtr: mhi: synchronize qrtr and mhi preparation |
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On 2021-07-20 18:42, Bhaumik Bhatt wrote: > A dl callback can be received anytime after mhi_prepare_for_transfer > has been called. There is a window where the callback may happen > before the probe initializes the qrtr_mhi_dev state. Move the > mhi_prepare_for_transfer call after the registering the endpoint. > > Once moved, the reverse can happen where qrtr will try to send a packet > before the channels are prepared. Add a wait in the sending path to > ensure the channels are prepared before trying to do a ul transfer. > > Fixes: a2e2cc0dbb11 ("net: qrtr: Start MHI channels during init") > Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org> > --- > net/qrtr/mhi.c | 20 +++++++++++++++----- > 1 file changed, 15 insertions(+), 5 deletions(-) > > diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c > index 29b4fa3..22b0395 100644 > --- a/net/qrtr/mhi.c > +++ b/net/qrtr/mhi.c > @@ -15,6 +15,7 @@ struct qrtr_mhi_dev { > struct qrtr_endpoint ep; > struct mhi_device *mhi_dev; > struct device *dev; > + struct completion ready; > }; > > /* From MHI to QRTR */ > @@ -50,6 +51,10 @@ static int qcom_mhi_qrtr_send(struct qrtr_endpoint > *ep, struct sk_buff *skb) > struct qrtr_mhi_dev *qdev = container_of(ep, struct qrtr_mhi_dev, > ep); > int rc; > > + rc = wait_for_completion_interruptible(&qdev->ready); > + if (rc) > + goto free_skb; > + > if (skb->sk) > sock_hold(skb->sk); > > @@ -78,11 +83,6 @@ static int qcom_mhi_qrtr_probe(struct mhi_device > *mhi_dev, > struct qrtr_mhi_dev *qdev; > int rc; > > - /* start channels */ > - rc = mhi_prepare_for_transfer(mhi_dev, MHI_CH_INBOUND_ALLOC_BUFS); > - if (rc) > - return rc; > - > qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL); > if (!qdev) > return -ENOMEM; would it be good to init completion variable here (call init_completion) ? > @@ -90,12 +90,22 @@ static int qcom_mhi_qrtr_probe(struct mhi_device > *mhi_dev, > qdev->mhi_dev = mhi_dev; > qdev->dev = &mhi_dev->dev; > qdev->ep.xmit = qcom_mhi_qrtr_send; > + init_completion(&qdev->ready); >
> > return 0;
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