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| author | Bjorn Andersson <bjorn.andersson@linaro.org> | 2018-02-13 11:04:04 -0800 |
|---|---|---|
| committer | Bjorn Andersson <bjorn.andersson@linaro.org> | 2018-03-20 10:52:54 +0800 |
| commit | 29fc9b3873607d01b1ff1ae077982cf5629010af (patch) | |
| tree | df164e56cfbaebac29baf4f92352769029838e6c /drivers/rpmsg | |
| parent | 33e3820dda8876792bd8135db633c741a07263be (diff) | |
| download | lwn-29fc9b3873607d01b1ff1ae077982cf5629010af.tar.gz lwn-29fc9b3873607d01b1ff1ae077982cf5629010af.zip | |
rpmsg: glink: Use spinlock in tx path
Switch the tx_lock to a spinlock we allow clients to use rpmsg_trysend()
from atomic context.
In order to allow clients to sleep while waiting for space in the FIFO
we release the lock temporarily around the delay; which should be
replaced by sending a READ_NOTIF and waiting for the remote to signal
us that space has been made available.
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Diffstat (limited to 'drivers/rpmsg')
| -rw-r--r-- | drivers/rpmsg/qcom_glink_native.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c index e0f31ed096a5..768ef542a841 100644 --- a/drivers/rpmsg/qcom_glink_native.c +++ b/drivers/rpmsg/qcom_glink_native.c @@ -113,7 +113,7 @@ struct qcom_glink { spinlock_t rx_lock; struct list_head rx_queue; - struct mutex tx_lock; + spinlock_t tx_lock; spinlock_t idr_lock; struct idr lcids; @@ -288,15 +288,14 @@ static int qcom_glink_tx(struct qcom_glink *glink, const void *data, size_t dlen, bool wait) { unsigned int tlen = hlen + dlen; - int ret; + unsigned long flags; + int ret = 0; /* Reject packets that are too big */ if (tlen >= glink->tx_pipe->length) return -EINVAL; - ret = mutex_lock_interruptible(&glink->tx_lock); - if (ret) - return ret; + spin_lock_irqsave(&glink->tx_lock, flags); while (qcom_glink_tx_avail(glink) < tlen) { if (!wait) { @@ -304,7 +303,12 @@ static int qcom_glink_tx(struct qcom_glink *glink, goto out; } + /* Wait without holding the tx_lock */ + spin_unlock_irqrestore(&glink->tx_lock, flags); + usleep_range(10000, 15000); + + spin_lock_irqsave(&glink->tx_lock, flags); } qcom_glink_tx_write(glink, hdr, hlen, data, dlen); @@ -313,7 +317,7 @@ static int qcom_glink_tx(struct qcom_glink *glink, mbox_client_txdone(glink->mbox_chan, 0); out: - mutex_unlock(&glink->tx_lock); + spin_unlock_irqrestore(&glink->tx_lock, flags); return ret; } @@ -1567,7 +1571,7 @@ struct qcom_glink *qcom_glink_native_probe(struct device *dev, glink->features = features; glink->intentless = intentless; - mutex_init(&glink->tx_lock); + spin_lock_init(&glink->tx_lock); spin_lock_init(&glink->rx_lock); INIT_LIST_HEAD(&glink->rx_queue); INIT_WORK(&glink->rx_work, qcom_glink_work); |