diff options
| author |   Shengjiu Wang <shengjiu.wang@nxp.com> | 2022-03-28 10:20:11 +0800 |
|---|---|---|
| committer |   Mathieu Poirier <mathieu.poirier@linaro.org> | 2022-04-14 11:08:26 -0600 |
| commit | 8f454f950dbb663180f596db18c3dc7ec26497f0 (patch) | |
| tree | 5e823280a53f91e418ecfe92a7f78adcf1e6a30d /drivers/remoteproc | |
| parent | remoteproc: imx_dsp_rproc: Make rsc_table optional (diff) | |
| download | wireguard-linux-8f454f950dbb663180f596db18c3dc7ec26497f0.tar.xz wireguard-linux-8f454f950dbb663180f596db18c3dc7ec26497f0.zip | |
remoteproc: core: Remove state checking before calling rproc_boot()
There is no mutex protection of the state checking before rproc_boot(),
which can't guarantee there is no another instance is trying to do
same operation.
Consider two instances case:
Instance1: echo start > /sys/class/remoteproc/remoteproc0/state
Instance2: echo start > /sys/class/remoteproc/remoteproc0/state
...
Instance2: echo stop > /sys/class/remoteproc/remoteproc0/state
...
Instance1: echo stop > /sys/class/remoteproc/remoteproc0/state
The one issue is that the instance2 case may success when 'start'
happens at same time as instance1, then rproc->power = 2; Or it
may fail with -BUSY, then rproc->power = 1; which is uncertain.
The another issue is for 'stop' operation, if the rproc->power = 1,
when instance2 'stop' the remoteproc the instance1 will be
impacted for it still needs the service at that time.
The reference counter rproc->power is used to manage state
changing and there is mutex protection in each operation
function for multi instance case.
So remove this state checking in rproc_cdev_write() and
state_store() for 'start' operation, just let reference
counter rproc->power to manage the behaviors.
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://lore.kernel.org/r/1648434012-16655-2-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Diffstat (limited to 'drivers/remoteproc')
| -rw-r--r-- | drivers/remoteproc/remoteproc_cdev.c | 4 | ||||
| -rw-r--r-- | drivers/remoteproc/remoteproc_sysfs.c | 4 |
2 files changed, 0 insertions, 8 deletions
diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c index 906ff3c4dfdd..62001eda780c 100644 --- a/drivers/remoteproc/remoteproc_cdev.c +++ b/drivers/remoteproc/remoteproc_cdev.c @@ -32,10 +32,6 @@ static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, size_ return -EFAULT; if (!strncmp(cmd, "start", len)) { - if (rproc->state == RPROC_RUNNING || - rproc->state == RPROC_ATTACHED) - return -EBUSY; - ret = rproc_boot(rproc); } else if (!strncmp(cmd, "stop", len)) { if (rproc->state != RPROC_RUNNING && diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c index 51a04bc6ba7a..ac64d69085ab 100644 --- a/drivers/remoteproc/remoteproc_sysfs.c +++ b/drivers/remoteproc/remoteproc_sysfs.c @@ -194,10 +194,6 @@ static ssize_t state_store(struct device *dev, int ret = 0; if (sysfs_streq(buf, "start")) { - if (rproc->state == RPROC_RUNNING || - rproc->state == RPROC_ATTACHED) - return -EBUSY; - ret = rproc_boot(rproc); if (ret) dev_err(&rproc->dev, "Boot failed: %d\n", ret); |