On 07/29/2016 01:45 PM, Philipp Gesang wrote: > Introduce an attribute "inquiry_string" to the lun. > > In some environments, e. g. BIOS boot menus, the inquiry string > is the only information about devices presented to the user. The > default string depends on the "cdrom" bit of the first lun as > well as the kernel version and allows no further customization. > So without access to the client it is not obvious which gadget is > active at a given point and what any of the available luns might > contain. > > If "inquiry_string" is ignored or set to the empty string, the > old behavior is preserved. > > Signed-off-by: Philipp Gesang <philipp.gesang@xxxxxxxxxxxxx> > --- > drivers/usb/gadget/function/f_mass_storage.c | 22 +++++++++++++++++++++- > drivers/usb/gadget/function/f_mass_storage.h | 1 + > drivers/usb/gadget/function/storage_common.c | 24 ++++++++++++++++++++++++ > drivers/usb/gadget/function/storage_common.h | 4 ++++ > 4 files changed, 50 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c > index 2505117..47d8248 100644 > --- a/drivers/usb/gadget/function/f_mass_storage.c > +++ b/drivers/usb/gadget/function/f_mass_storage.c > @@ -1107,7 +1107,12 @@ static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh) > buf[5] = 0; /* No special options */ > buf[6] = 0; > buf[7] = 0; > - memcpy(buf + 8, common->inquiry_string, sizeof common->inquiry_string); > + if (curlun->inquiry_string[0]) > + memcpy(buf + 8, curlun->inquiry_string, > + sizeof(curlun->inquiry_string)); > + else > + memcpy(buf + 8, common->inquiry_string, > + sizeof(common->inquiry_string)); > return 36; > } > > @@ -3209,12 +3214,27 @@ static ssize_t fsg_lun_opts_nofua_store(struct config_item *item, > > CONFIGFS_ATTR(fsg_lun_opts_, nofua); > > +static ssize_t fsg_lun_opts_inquiry_string_show(struct config_item *item, > + char *page) > +{ > + return fsg_show_inquiry_string(to_fsg_lun_opts(item)->lun, page); > +} > + > +static ssize_t fsg_lun_opts_inquiry_string_store(struct config_item *item, > + const char *page, size_t len) > +{ > + return fsg_store_inquiry_string(to_fsg_lun_opts(item)->lun, page, len); > +} > + > +CONFIGFS_ATTR(fsg_lun_opts_, inquiry_string); > + > static struct configfs_attribute *fsg_lun_attrs[] = { > &fsg_lun_opts_attr_file, > &fsg_lun_opts_attr_ro, > &fsg_lun_opts_attr_removable, > &fsg_lun_opts_attr_cdrom, > &fsg_lun_opts_attr_nofua, > + &fsg_lun_opts_attr_inquiry_string, > NULL, > }; > > diff --git a/drivers/usb/gadget/function/f_mass_storage.h b/drivers/usb/gadget/function/f_mass_storage.h > index b6a9918..99ac7ad 100644 > --- a/drivers/usb/gadget/function/f_mass_storage.h > +++ b/drivers/usb/gadget/function/f_mass_storage.h > @@ -100,6 +100,7 @@ struct fsg_lun_config { > char removable; > char cdrom; > char nofua; > + char inquiry_string[8 + 16 + 4 + 1]; Could you please make those calculations as some define (as they exist in at least two places) and add some comments about meaning of those magic numbers? > }; > > struct fsg_config { > diff --git a/drivers/usb/gadget/function/storage_common.c b/drivers/usb/gadget/function/storage_common.c > index 990df22..9b56859 100644 > --- a/drivers/usb/gadget/function/storage_common.c > +++ b/drivers/usb/gadget/function/storage_common.c > @@ -369,6 +369,12 @@ ssize_t fsg_show_removable(struct fsg_lun *curlun, char *buf) > } > EXPORT_SYMBOL_GPL(fsg_show_removable); > > +ssize_t fsg_show_inquiry_string(struct fsg_lun *curlun, char *buf) > +{ > + return sprintf(buf, "%s\n", curlun->inquiry_string); > +} > +EXPORT_SYMBOL_GPL(fsg_show_inquiry_string); > + > /* > * The caller must hold fsg->filesem for reading when calling this function. > */ > @@ -499,4 +505,22 @@ ssize_t fsg_store_removable(struct fsg_lun *curlun, const char *buf, > } > EXPORT_SYMBOL_GPL(fsg_store_removable); > > +ssize_t fsg_store_inquiry_string(struct fsg_lun *curlun, const char *buf, > + size_t count) > +{ > + const size_t len = min(count, sizeof(curlun->inquiry_string)); > + > + if (len == 0 || buf[0] == '\n') > + curlun->inquiry_string[0] = 0; > + else { > + snprintf(curlun->inquiry_string, > + sizeof(curlun->inquiry_string), "%-28s", buf); > + if (curlun->inquiry_string[len-1] == '\n') > + curlun->inquiry_string[len-1] = ' '; > + } According to codding style you should probably do: if (...) { instruction; } else { instruction; instruction; /* ... */ } in this case. > + > + return count; > +} > +EXPORT_SYMBOL_GPL(fsg_store_inquiry_string); > + > MODULE_LICENSE("GPL"); > diff --git a/drivers/usb/gadget/function/storage_common.h b/drivers/usb/gadget/function/storage_common.h > index c3544e6..af74044 100644 > --- a/drivers/usb/gadget/function/storage_common.h > +++ b/drivers/usb/gadget/function/storage_common.h > @@ -112,6 +112,7 @@ struct fsg_lun { > struct device dev; > const char *name; /* "lun.name" */ > const char **name_pfx; /* "function.name" */ > + char inquiry_string[8 + 16 + 4 + 1]; Just like I wrote above. Please make define for size of this array. Best regards, -- Krzysztof Opasiak Samsung R&D Institute Poland Samsung Electronics -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html