drivers/misc/ti-st: fix read fw version cmd

If the read firmware version response from the chip is split into multiple
frames of UART buffer being received by the host, the TI-ST driver as of today
is unable to put the pieces of response together unlike other responses.

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

1 files changed, 27 insertions, 13 deletions

diff --git a/drivers/misc/ti-st/st_kim.c b/drivers/misc/ti-st/st_kim.c
index 0f36db3aa40f..04a819944f6b 100644
--- a/drivers/misc/ti-st/st_kim.c
+++ b/drivers/misc/ti-st/st_kim.c
@@ -66,7 +66,24 @@ static struct platform_device *st_get_plat_device(int id)
 static void validate_firmware_response(struct kim_data_s *kim_gdata)
 {
         struct sk_buff *skb = kim_gdata->rx_skb;
-        if (unlikely(skb->data[5] != 0)) {
+        if (!skb)
+                return;
+
+        /* these magic numbers are the position in the response buffer which
+         * allows us to distinguish whether the response is for the read
+         * version info. command
+         */
+        if (skb->data[2] == 0x01 && skb->data[3] == 0x01 &&
+                        skb->data[4] == 0x10 && skb->data[5] == 0x00) {
+                /* fw version response */
+                memcpy(kim_gdata->resp_buffer,
+                                kim_gdata->rx_skb->data,
+                                kim_gdata->rx_skb->len);
+                complete_all(&kim_gdata->kim_rcvd);
+                kim_gdata->rx_state = ST_W4_PACKET_TYPE;
+                kim_gdata->rx_skb = NULL;
+                kim_gdata->rx_count = 0;
+        } else if (unlikely(skb->data[5] != 0)) {
                 pr_err("no proper response during fw download");
                 pr_err("data6 %x", skb->data[5]);
                 kfree_skb(skb);
@@ -213,10 +230,13 @@ static long read_local_version(struct kim_data_s *kim_gdata, char *bts_scr_name)
                 return -ETIMEDOUT;
         }
         INIT_COMPLETION(kim_gdata->kim_rcvd);
+        /* the positions 12 & 13 in the response buffer provide with the
+         * chip, major & minor numbers
+         */
 
         version =
-                MAKEWORD(kim_gdata->resp_buffer[13],
-                                kim_gdata->resp_buffer[14]);
+                MAKEWORD(kim_gdata->resp_buffer[12],
+                                kim_gdata->resp_buffer[13]);
         chip = (version & 0x7C00) >> 10;
         min_ver = (version & 0x007F);
         maj_ver = (version & 0x0380) >> 7;
@@ -410,16 +430,10 @@ void st_kim_recv(void *disc_data, const unsigned char *data, long count)
         struct st_data_s        *st_gdata = (struct st_data_s *)disc_data;
         struct kim_data_s       *kim_gdata = st_gdata->kim_data;
 
-        /* copy to local buffer */
-        if (unlikely(data[4] == 0x01 && data[5] == 0x10 && data[0] == 0x04)) {
-                /* must be the read_ver_cmd */
-                memcpy(kim_gdata->resp_buffer, data, count);
-                complete_all(&kim_gdata->kim_rcvd);
-                return;
-        } else {
-                kim_int_recv(kim_gdata, data, count);
-                /* either completes or times out */
-        }
+        /* proceed to gather all data and distinguish read fw version response
+         * from other fw responses when data gathering is complete
+         */
+        kim_int_recv(kim_gdata, data, count);
         return;
 }