Messages in this thread | | | Date | Sun, 18 Mar 2018 15:47:36 -0700 | From | Bjorn Andersson <> | Subject | Re: [PATCH RESEND] rpmsg: Add driver_override device attribute for rpmsg_device |
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On Wed 10 Jan 05:17 PST 2018, Anup Patel wrote:
> This patch adds "driver_override" device attribute for rpmsg_device which > will allow users to explicitly specify the rpmsg_driver to be used via > sysfs entry. > > The "driver_override" device attribute implemented here is very similar > to "driver_override" implemented for platform, pci, and amba bus types. > > One important use-case of "driver_override" device attribute is to force > use of rpmsg_chrdev driver for certain rpmsg_device instances. >
I assume you mean specifically for the case where you want to prevent some kernel driver to probe for some given channel?
The intention with rpmsg_char is that you through the rpmsg_ctrlX interface create and destroy endpoints dynamically, so you wouldn't need to use this mechanism to bind some specific channel to rpmsg_char.
That said, this does make sense for completeness sake.
[..] > diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c > index dffa3aa..9a25e42 100644 > --- a/drivers/rpmsg/rpmsg_core.c > +++ b/drivers/rpmsg/rpmsg_core.c > @@ -321,11 +321,11 @@ struct device *rpmsg_find_device(struct device *parent, > } > EXPORT_SYMBOL(rpmsg_find_device); > > -/* sysfs show configuration fields */ > +/* sysfs configuration fields */ > #define rpmsg_show_attr(field, path, format_string) \ > static ssize_t \ > field##_show(struct device *dev, \ > - struct device_attribute *attr, char *buf) \ > + struct device_attribute *attr, char *buf) \
Seems unnecessary.
> { \ > struct rpmsg_device *rpdev = to_rpmsg_device(dev); \ > \ > @@ -333,11 +333,52 @@ field##_show(struct device *dev, \ > } \ > static DEVICE_ATTR_RO(field); > > +#define rpmsg_string_attr(field, path) \
"path" is an odd name for these, I think it's a "member".
> +static ssize_t \ > +field##_store(struct device *dev, \ > + struct device_attribute *attr, const char *buf, size_t sz)\
field##_store(struct device *dev, struct device_attribute *attr, \ const char *buf, size_t sz) \
Is prettier
> +{ \ > + struct rpmsg_device *rpdev = to_rpmsg_device(dev); \ > + char *new, *old, *cp; \ > + \ > + new = kstrndup(buf, sz, GFP_KERNEL); \ > + if (!new) \ > + return -ENOMEM; \ > + \ > + cp = strchr(new, '\n'); \ > + if (cp) \ > + *cp = '\0'; \
I prefer
new[strcspn(new, "\n")] = '\0';
Regards, Bjorn
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