| Message ID | 20200424200135.28825-12-mathieu.poirier@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | remoteproc: Add support for synchronisaton with rproc | expand |
On 4/24/20 10:01 PM, Mathieu Poirier wrote: > This patch prevents the firmware image from being displayed or changed > when the remoteproc core is synchronising with a remote processor. This > is needed since there is no guarantee about the nature of the firmware > image that is loaded by the external entity. > > Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> > --- > drivers/remoteproc/remoteproc_sysfs.c | 24 +++++++++++++++++++++++- > 1 file changed, 23 insertions(+), 1 deletion(-) > > diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c > index 7f8536b73295..cdd322a6ecfa 100644 > --- a/drivers/remoteproc/remoteproc_sysfs.c > +++ b/drivers/remoteproc/remoteproc_sysfs.c > @@ -13,9 +13,20 @@ > static ssize_t firmware_show(struct device *dev, struct device_attribute *attr, > char *buf) > { > + ssize_t ret; > struct rproc *rproc = to_rproc(dev); > > - return sprintf(buf, "%s\n", rproc->firmware); > + /* > + * In most instances there is no guarantee about the firmware > + * that was loaded by the external entity. As such simply don't > + * print anything. > + */ > + if (rproc_needs_syncing(rproc)) > + ret = sprintf(buf, "\n"); A default name is provided in sysfs if no firmware is started/synchronised on boot. IMO providing an empty name here could be confusing. Perhaps a refactoring of this sysfs entry would be nice: - Normal boot (no firmware loaded) : empty name instead of a default name - auto_boot: name provided by the platform driver or default name ( current implementation) - synchronization: a predefined name such as Default, unknown, External, None,... > + else > + ret = sprintf(buf, "%s\n", rproc->firmware); > + > + return ret; > } > > /* Change firmware name via sysfs */ > @@ -39,6 +50,17 @@ static ssize_t firmware_store(struct device *dev, > goto out; > } > > + /* > + * There is no point in trying to change the firmware if loading the > + * image of the remote processor is done by another entity. > + */ > + if (rproc_needs_syncing(rproc)) { > + dev_err(dev, > + "can't change firmware while synchronising with MCU\n"); I don't know if you decide to keep "MCU" or not. If not the case you have also some other instances in your patch 9/14. Regards Arnaud > + err = -EBUSY; > + goto out; > + } > + > len = strcspn(buf, "\n"); > if (!len) { > dev_err(dev, "can't provide a NULL firmware\n"); >
On Wed, Apr 29, 2020 at 10:52:48AM +0200, Arnaud POULIQUEN wrote: > > > On 4/24/20 10:01 PM, Mathieu Poirier wrote: > > This patch prevents the firmware image from being displayed or changed > > when the remoteproc core is synchronising with a remote processor. This > > is needed since there is no guarantee about the nature of the firmware > > image that is loaded by the external entity. > > > > Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> > > --- > > drivers/remoteproc/remoteproc_sysfs.c | 24 +++++++++++++++++++++++- > > 1 file changed, 23 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c > > index 7f8536b73295..cdd322a6ecfa 100644 > > --- a/drivers/remoteproc/remoteproc_sysfs.c > > +++ b/drivers/remoteproc/remoteproc_sysfs.c > > @@ -13,9 +13,20 @@ > > static ssize_t firmware_show(struct device *dev, struct device_attribute *attr, > > char *buf) > > { > > + ssize_t ret; > > struct rproc *rproc = to_rproc(dev); > > > > - return sprintf(buf, "%s\n", rproc->firmware); > > + /* > > + * In most instances there is no guarantee about the firmware > > + * that was loaded by the external entity. As such simply don't > > + * print anything. > > + */ > > + if (rproc_needs_syncing(rproc)) > > + ret = sprintf(buf, "\n"); > > A default name is provided in sysfs if no firmware is started/synchronised on boot. > > IMO providing an empty name here could be confusing. > Perhaps a refactoring of this sysfs entry would be nice: > - Normal boot (no firmware loaded) : empty name instead of a default name That is guaranteed to break user space so we can't proceed this way. > - auto_boot: name provided by the platform driver or default name ( current implementation) > - synchronization: a predefined name such as Default, unknown, External, None,... Loic had the same comment. Usually it is best to provide sysfs output that don't need parsing, i.e 0/1 or nothing at all, but in the remoteproc subsystem we already have "state", "name" and "firmware" that need parsing. As such my next revision will have "unknown", which I think is the best way to describe the situation. > > > + else > > + ret = sprintf(buf, "%s\n", rproc->firmware); > > + > > + return ret; > > } > > > > /* Change firmware name via sysfs */ > > @@ -39,6 +50,17 @@ static ssize_t firmware_store(struct device *dev, > > goto out; > > } > > > > + /* > > + * There is no point in trying to change the firmware if loading the > > + * image of the remote processor is done by another entity. > > + */ > > + if (rproc_needs_syncing(rproc)) { > > + dev_err(dev, > > + "can't change firmware while synchronising with MCU\n"); > > I don't know if you decide to keep "MCU" or not. If not the case > you have also some other instances in your patch 9/14. MCU should be long gone. I thought I had spotted them all but was obviously wrong. > > Regards > Arnaud > > > + err = -EBUSY; > > + goto out; > > + } > > + > > len = strcspn(buf, "\n"); > > if (!len) { > > dev_err(dev, "can't provide a NULL firmware\n"); > >
On Fri 24 Apr 13:01 PDT 2020, Mathieu Poirier wrote: > This patch prevents the firmware image from being displayed or changed > when the remoteproc core is synchronising with a remote processor. This > is needed since there is no guarantee about the nature of the firmware > image that is loaded by the external entity. > > Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> > --- > drivers/remoteproc/remoteproc_sysfs.c | 24 +++++++++++++++++++++++- > 1 file changed, 23 insertions(+), 1 deletion(-) > > diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c > index 7f8536b73295..cdd322a6ecfa 100644 > --- a/drivers/remoteproc/remoteproc_sysfs.c > +++ b/drivers/remoteproc/remoteproc_sysfs.c > @@ -13,9 +13,20 @@ > static ssize_t firmware_show(struct device *dev, struct device_attribute *attr, > char *buf) > { > + ssize_t ret; > struct rproc *rproc = to_rproc(dev); > > - return sprintf(buf, "%s\n", rproc->firmware); > + /* > + * In most instances there is no guarantee about the firmware > + * that was loaded by the external entity. As such simply don't > + * print anything. Not only "in most instances", we have no idea what firmware is running, so this can be shortened. However, this does implicate that on_init = true, after_crash = false, this will read blank, but a future rproc_report_crash() will indeed load and boot rproc->firmware. > + */ > + if (rproc_needs_syncing(rproc)) > + ret = sprintf(buf, "\n"); > + else > + ret = sprintf(buf, "%s\n", rproc->firmware); > + > + return ret; > } > > /* Change firmware name via sysfs */ > @@ -39,6 +50,17 @@ static ssize_t firmware_store(struct device *dev, > goto out; > } > > + /* > + * There is no point in trying to change the firmware if loading the > + * image of the remote processor is done by another entity. > + */ > + if (rproc_needs_syncing(rproc)) { > + dev_err(dev, > + "can't change firmware while synchronising with MCU\n"); The conditional checks for a future event, but the error message indicates an ongoing event. How about "can't change firmware on remote controlled remote processor"? "externally controlled"? Regards, Bjorn > + err = -EBUSY; > + goto out; > + } > + > len = strcspn(buf, "\n"); > if (!len) { > dev_err(dev, "can't provide a NULL firmware\n"); > -- > 2.20.1 >
diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c index 7f8536b73295..cdd322a6ecfa 100644 --- a/drivers/remoteproc/remoteproc_sysfs.c +++ b/drivers/remoteproc/remoteproc_sysfs.c @@ -13,9 +13,20 @@ static ssize_t firmware_show(struct device *dev, struct device_attribute *attr, char *buf) { + ssize_t ret; struct rproc *rproc = to_rproc(dev); - return sprintf(buf, "%s\n", rproc->firmware); + /* + * In most instances there is no guarantee about the firmware + * that was loaded by the external entity. As such simply don't + * print anything. + */ + if (rproc_needs_syncing(rproc)) + ret = sprintf(buf, "\n"); + else + ret = sprintf(buf, "%s\n", rproc->firmware); + + return ret; } /* Change firmware name via sysfs */ @@ -39,6 +50,17 @@ static ssize_t firmware_store(struct device *dev, goto out; } + /* + * There is no point in trying to change the firmware if loading the + * image of the remote processor is done by another entity. + */ + if (rproc_needs_syncing(rproc)) { + dev_err(dev, + "can't change firmware while synchronising with MCU\n"); + err = -EBUSY; + goto out; + } + len = strcspn(buf, "\n"); if (!len) { dev_err(dev, "can't provide a NULL firmware\n");
This patch prevents the firmware image from being displayed or changed when the remoteproc core is synchronising with a remote processor. This is needed since there is no guarantee about the nature of the firmware image that is loaded by the external entity. Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> --- drivers/remoteproc/remoteproc_sysfs.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-)