media: b2c2: flexcop-usb: fix flexcop_usb_memory_req

smatch generated this warning:

drivers/media/usb/b2c2/flexcop-usb.c:199 flexcop_usb_memory_req() warn: iterator 'i' not incremented

and indeed the function is not using i or updating buf.

The reason this always worked is that this function is called to write just
6 bytes (a MAC address) to the USB device, and so in practice there is only
a single chunk written. If we ever would need to write more than one chunk,
this function would fail since each chunk would read from or write to the
same buf address.

Rewrite the function to properly handle this.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

diff --git a/drivers/media/usb/b2c2/flexcop-usb.c b/drivers/media/usb/b2c2/flexcop-usb.c
index 90f1aea99dac054e0917e77a595980332d68263a..8033622543f2893c48d837aeb614f3201a95874a 100644 (file)
--- a/drivers/media/usb/b2c2/flexcop-usb.c
+++ b/drivers/media/usb/b2c2/flexcop-usb.c
@@ -179,7 +179,7 @@ static int flexcop_usb_memory_req(struct flexcop_usb *fc_usb,
                flexcop_usb_request_t req, flexcop_usb_mem_page_t page_start,
                u32 addr, int extended, u8 *buf, u32 len)
 {
-       int i, ret = 0;
+       int ret = 0;
        u16 wMax;
        u32 pagechunk = 0;
 
@@ -196,7 +196,7 @@ static int flexcop_usb_memory_req(struct flexcop_usb *fc_usb,
        default:
                return -EINVAL;
        }
-       for (i = 0; i < len;) {
+       while (len) {
                pagechunk = min(wMax, bytes_left_to_read_on_page(addr, len));
                deb_info("%x\n",
                        (addr & V8_MEMORY_PAGE_MASK) |
@@ -206,11 +206,12 @@ static int flexcop_usb_memory_req(struct flexcop_usb *fc_usb,
                        page_start + (addr / V8_MEMORY_PAGE_SIZE),
                        (addr & V8_MEMORY_PAGE_MASK) |
                                (V8_MEMORY_EXTENDED*extended),
-                       &buf[i], pagechunk);
+                       buf, pagechunk);
 
                if (ret < 0)
                        return ret;
                addr += pagechunk;
+               buf += pagechunk;
                len -= pagechunk;
        }
        return 0;