ntb: idt: fix clang -Wformat warnings

When building with Clang we encounter these warnings:
| drivers/ntb/hw/idt/ntb_hw_idt.c:2409:28: error: format specifies type
| 'unsigned char' but the argument has type 'int' [-Werror,-Wformat]
| "\t%hhu-%hhu.\t", idx + cnt - 1);
-
| drivers/ntb/hw/idt/ntb_hw_idt.c:2438:29: error: format specifies type
| 'unsigned char' but the argument has type 'int' [-Werror,-Wformat]
| "\t%hhu-%hhu.\t", idx + cnt - 1);
-
| drivers/ntb/hw/idt/ntb_hw_idt.c:2484:15: error: format specifies type
| 'unsigned char' but the argument has type 'int' [-Werror,-Wformat], src);

For the first two warnings the format specifier used is `%hhu` which
describes a u8. Both `idx` and `cnt` are u8 as well. However, the
expression as a whole is promoted to an int as you cannot get
smaller-than-int from addition. Therefore, to fix the warning, use the
promoted-to-type's format specifier -- in this case `%d`.

example:
``
uint8_t a = 4, b = 7;
int size = sizeof(a + b - 1);
printf("%d\n", size);
// output: 4
```

For the last warning, src is of type `int` while the format specifier
describes a u8. The fix here is just to use the proper specifier `%d`.

See more:
(https://wiki.sei.cmu.edu/confluence/display/c/INT02-C.+Understand+integer+conversion+rules)
"Integer types smaller than int are promoted when an operation is
performed on them. If all values of the original type can be represented
as an int, the value of the smaller type is converted to an int;
otherwise, it is converted to an unsigned int."

Link: https://github.com/ClangBuiltLinux/linux/issues/378
Signed-off-by: Justin Stitt <justinstitt@google.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

diff --git a/drivers/ntb/hw/idt/ntb_hw_idt.c b/drivers/ntb/hw/idt/ntb_hw_idt.c
index 733557231ed0bd8215f5e7d02eb81b895884720e..0ed6f809ff2eebb41c78a263fa125ad0c2a70db3 100644 (file)
--- a/drivers/ntb/hw/idt/ntb_hw_idt.c
+++ b/drivers/ntb/hw/idt/ntb_hw_idt.c
@@ -2406,7 +2406,7 @@ static ssize_t idt_dbgfs_info_read(struct file *filp, char __user *ubuf,
                                "\t%hhu.\t", idx);
                else
                        off += scnprintf(strbuf + off, size - off,
-                               "\t%hhu-%hhu.\t", idx, idx + cnt - 1);
+                               "\t%hhu-%d.\t", idx, idx + cnt - 1);
 
                off += scnprintf(strbuf + off, size - off, "%s BAR%hhu, ",
                        idt_get_mw_name(data), ndev->mws[idx].bar);
@@ -2435,7 +2435,7 @@ static ssize_t idt_dbgfs_info_read(struct file *filp, char __user *ubuf,
                                        "\t%hhu.\t", idx);
                        else
                                off += scnprintf(strbuf + off, size - off,
-                                       "\t%hhu-%hhu.\t", idx, idx + cnt - 1);
+                                       "\t%hhu-%d.\t", idx, idx + cnt - 1);
 
                        off += scnprintf(strbuf + off, size - off,
                                "%s BAR%hhu, ", idt_get_mw_name(data),
@@ -2480,7 +2480,7 @@ static ssize_t idt_dbgfs_info_read(struct file *filp, char __user *ubuf,
                int src;
                data = idt_ntb_msg_read(&ndev->ntb, &src, idx);
                off += scnprintf(strbuf + off, size - off,
-                       "\t%hhu. 0x%08x from peer %hhu (Port %hhu)\n",
+                       "\t%hhu. 0x%08x from peer %d (Port %hhu)\n",
                        idx, data, src, ndev->peers[src].port);
        }
        off += scnprintf(strbuf + off, size - off, "\n");