drivers:misc: ti-st: fix error codes

set-right the error codes that the shared transport driver
returns.
Instead of magic numbers like -1, return relevant codes such as
ETIMEDOUT or EIO, EAGAIN when wait times out or uart write bytes don't
match expected value or when registration fails and needs to be
attempted again.

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 14 insertions, 17 deletions

diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
index 84d73c5cb74d..79d2dc3fca1f 100644
--- a/drivers/misc/ti-st/st_core.c
+++ b/drivers/misc/ti-st/st_core.c
@@ -65,7 +65,7 @@ int st_int_write(struct st_data_s *st_gdata,
         struct tty_struct *tty;
         if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
                 pr_err("tty unavailable to perform write");
-                return -1;
+                return -EINVAL;
         }
         tty = st_gdata->tty;
 #ifdef VERBOSE
@@ -124,9 +124,15 @@ void st_reg_complete(struct st_data_s *st_gdata, char err)
         pr_info(" %s ", __func__);
         for (i = 0; i < ST_MAX_CHANNELS; i++) {
                 if (likely(st_gdata != NULL && st_gdata->list[i] != NULL &&
-                           st_gdata->list[i]->reg_complete_cb != NULL))
+                           st_gdata->list[i]->reg_complete_cb != NULL)) {
                         st_gdata->list[i]->reg_complete_cb
                                 (st_gdata->list[i]->priv_data, err);
+                        pr_info("protocol %d's cb sent %d\n", i, err);
+                        if (err) { /* cleanup registered protocol */
+                                st_gdata->protos_registered--;
+                                st_gdata->list[i] = NULL;
+                        }
+                }
         }
 }
 
@@ -457,15 +463,7 @@ long st_register(struct st_proto_s *new_proto)
         if (st_gdata == NULL || new_proto == NULL || new_proto->recv == NULL
             || new_proto->reg_complete_cb == NULL) {
                 pr_err("gdata/new_proto/recv or reg_complete_cb not ready");
-                if (st_gdata == NULL)
-                        pr_err("error 1\n");
-                if (new_proto == NULL)
-                        pr_err("error 2\n");
-                if (new_proto->recv == NULL)
-                        pr_err("error 3\n");
-                if (new_proto->reg_complete_cb == NULL)
-                        pr_err("erro 4\n");
-                return -1;
+                return -EINVAL;
         }
 
         if (new_proto->chnl_id >= ST_MAX_CHANNELS) {
@@ -512,10 +510,9 @@ long st_register(struct st_proto_s *new_proto)
                         if ((st_gdata->protos_registered != ST_EMPTY) &&
                             (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
                                 pr_err(" KIM failure complete callback ");
-                                st_reg_complete(st_gdata, -1);
+                                st_reg_complete(st_gdata, err);
                         }
-
-                        return -1;
+                        return -EINVAL;
                 }
 
                 /* the chnl_id might require other gpios to be toggled
@@ -634,14 +631,14 @@ long st_write(struct sk_buff *skb)
         if (unlikely(skb == NULL || st_gdata == NULL
                 || st_gdata->tty == NULL)) {
                 pr_err("data/tty unavailable to perform write");
-                return -1;
+                return -EINVAL;
         }
 #ifdef DEBUG                    /* open-up skb to read the 1st byte */
         chnl_id = skb->data[0];
         if (unlikely(st_gdata->list[chnl_id] == NULL)) {
                 pr_err(" chnl_id %d not registered, and writing? ",
                            chnl_id);
-                return -1;
+                return -EINVAL;
         }
 #endif
         pr_debug("%d to be written", skb->len);
@@ -829,7 +826,7 @@ int st_core_init(struct st_data_s **core_data)
                 err = tty_unregister_ldisc(N_TI_WL);
                 if (err)
                         pr_err("unable to un-register ldisc");
-                return -1;
+                return err;
         }
         *core_data = st_gdata;
         return 0;