firewire: Kill unnecessary buf check in device_attribute.show

Per Documentation/filesystems/sysfs.rst:
> sysfs allocates a buffer of size (PAGE_SIZE) and passes it to the
> method.

So we can kill the unnecessary buf check safely.

Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Link: https://lore.kernel.org/r/20240122053942.80648-1-lizhijian@fujitsu.com
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c
index 7d3346b3a2bf320910c72783ab857415d331ed14..3a1a2bf1717ccf4d6802b9a85ab777dbd9f44905 100644 (file)
--- a/drivers/firewire/core-device.c
+++ b/drivers/firewire/core-device.c
@@ -322,7 +322,7 @@ static ssize_t show_immediate(struct device *dev,
        if (value < 0)
                return -ENOENT;
 
-       return snprintf(buf, buf ? PAGE_SIZE : 0, "0x%06x\n", value);
+       return snprintf(buf, PAGE_SIZE, "0x%06x\n", value);
 }
 
 #define IMMEDIATE_ATTR(name, key)                              \
@@ -334,8 +334,6 @@ static ssize_t show_text_leaf(struct device *dev,
        struct config_rom_attribute *attr =
                container_of(dattr, struct config_rom_attribute, attr);
        const u32 *directories[] = {NULL, NULL};
-       size_t bufsize;
-       char dummy_buf[2];
        int i, ret = -ENOENT;
 
        down_read(&fw_device_rwsem);
@@ -357,15 +355,9 @@ static ssize_t show_text_leaf(struct device *dev,
                }
        }
 
-       if (buf) {
-               bufsize = PAGE_SIZE - 1;
-       } else {
-               buf = dummy_buf;
-               bufsize = 1;
-       }
-
        for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) {
-               int result = fw_csr_string(directories[i], attr->key, buf, bufsize);
+               int result = fw_csr_string(directories[i], attr->key, buf,
+                                          PAGE_SIZE - 1);
                // Detected.
                if (result >= 0) {
                        ret = result;