Kernel may decide to detach our gadget in some cases.
A good example is when FFS daemon received a SIGSEGV
and all descriptors has been closed.
To avoid returning false informations to user we have
to refresh UDC attribute before returning cached pointer
to usbg_udc.
Signed-off-by: Krzysztof Opasiak <k.opasiak@xxxxxxxxxxx>
---
src/usbg.c | 37 +++++++++++++++++++++++++++++++++++--
1 file changed, 35 insertions(+), 2 deletions(-)
diff --git a/src/usbg.c b/src/usbg.c
index b66c9b4..78490c1 100644
--- a/src/usbg.c
+++ b/src/usbg.c
@@ -1867,7 +1867,36 @@ int usbg_cpy_udc_name(usbg_udc *u, char *buf, size_t len)
usbg_udc *usbg_get_gadget_udc(usbg_gadget *g)
{
- return g ? g->udc : NULL;
+ usbg_udc *u = NULL;
+
+ if (!g)
+ goto out;
+ /*
+ * if gadget was enabled we have to check if kernel
+ * didn't modify the UDC file due to some errors.
+ * For example some FFS daemon could just get
+ * a segmentation fault or sth
+ */
+ if (g->udc) {
+ char buf[USBG_MAX_STR_LENGTH];
+ int ret;
+
+ ret = usbg_read_string(g->path, g->name, "UDC", buf);
+ if (ret != USBG_SUCCESS)
+ goto out;
+
+ if (!strcmp(g->udc->name, buf)) {
+ /* Gadget is still assigned to this UDC */
+ u = g->udc;
+ } else {
+ /* Kernel decided to detach this gadget */
+ g->udc->gadget = NULL;
+ g->udc = NULL;
+ }
+ }
+
+out:
+ return u;
}
int usbg_set_gadget_attrs(usbg_gadget *g, usbg_gadget_attrs *g_attrs)
@@ -2450,8 +2479,12 @@ int usbg_enable_gadget(usbg_gadget *g, usbg_udc *udc)
}
ret = usbg_write_string(g->path, g->name, "UDC", udc->name);
-
if (ret == USBG_SUCCESS) {
+ /* If gadget has been detached and we didn't noticed
+ * it we have to clean up now.
+ */
+ if (g->udc)
+ g->udc->gadget = NULL;
g->udc = udc;
udc->gadget = g;
}
--
1.7.9.5
--
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