Re: [patch] iwl: cleanup: remove unneeded error handling

From: Zhu Yi
Date: Wed Apr 28 2010 - 22:15:16 EST

On Wed, 2010-04-28 at 17:01 +0800, Dan Carpenter wrote:
> This is just a cleanup and doesn't change how the code works.
>
> debugfs_create_dir() and debugfs_create_file() return an error pointer
> (-ENODEV) if CONFIG_DEBUG_FS is not enabled, otherwise if an error occurs
> they return NULL. This is how they are implemented and what it says in
> the DebugFS documentation. DebugFS can not be compiled as a module.
>
> As a result, we only need to check for error pointers and particularly
> -ENODEV one time to know that DebugFS is enabled. This patch keeps the
> first check for error pointers and removes the rest.
>
> The other reason for this patch, is that it silences some Smatch warnings.
> Smatch sees the condition "(result != -ENODEV)" and assumes that it's
> possible for "result" to equal -ENODEV. If it were possible it would lead
> to an error pointer dereference. But since it's not, we can just remove
> the check.
>
> Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>

Thanks. But looks like you missed the one in if_sdio_debugfs_init().

I don't think we even need to check -ENODEV ourselves because if
DEBUG_FS is not compiled in, all the debugfs utility functions will
become no-op.

Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
Signed-off-by: Zhu Yi <yi.zhu@xxxxxxxxx>

diff --git a/drivers/net/wireless/iwmc3200wifi/bus.h b/drivers/net/wireless/iwmc3200wifi/bus.h
index 836663e..62edd58 100644
--- a/drivers/net/wireless/iwmc3200wifi/bus.h
+++ b/drivers/net/wireless/iwmc3200wifi/bus.h
@@ -31,7 +31,7 @@ struct iwm_if_ops {
int (*disable)(struct iwm_priv *iwm);
int (*send_chunk)(struct iwm_priv *iwm, u8* buf, int count);

- int (*debugfs_init)(struct iwm_priv *iwm, struct dentry *parent_dir);
+ void (*debugfs_init)(struct iwm_priv *iwm, struct dentry *parent_dir);
void (*debugfs_exit)(struct iwm_priv *iwm);

const char *umac_name;
diff --git a/drivers/net/wireless/iwmc3200wifi/debug.h b/drivers/net/wireless/iwmc3200wifi/debug.h
index e35c9b6..f98bf12 100644
--- a/drivers/net/wireless/iwmc3200wifi/debug.h
+++ b/drivers/net/wireless/iwmc3200wifi/debug.h
@@ -113,10 +113,10 @@ struct iwm_debugfs {
};

#ifdef CONFIG_IWM_DEBUG
-int iwm_debugfs_init(struct iwm_priv *iwm);
+void iwm_debugfs_init(struct iwm_priv *iwm);
void iwm_debugfs_exit(struct iwm_priv *iwm);
#else
-static inline int iwm_debugfs_init(struct iwm_priv *iwm)
+static inline void iwm_debugfs_init(struct iwm_priv *iwm)
{
return 0;
}
diff --git a/drivers/net/wireless/iwmc3200wifi/debugfs.c b/drivers/net/wireless/iwmc3200wifi/debugfs.c
index 7244413..53b0b77 100644
--- a/drivers/net/wireless/iwmc3200wifi/debugfs.c
+++ b/drivers/net/wireless/iwmc3200wifi/debugfs.c
@@ -48,12 +48,11 @@ static struct {

#define add_dbg_module(dbg, name, id, initlevel) \
do { \
- struct dentry *d; \
dbg.dbg_module[id] = (initlevel); \
- d = debugfs_create_x8(name, 0600, dbg.dbgdir, \
- &(dbg.dbg_module[id])); \
- if (!IS_ERR(d)) \
- dbg.dbg_module_dentries[id] = d; \
+ dbg.dbg_module_dentries[id] = \
+ debugfs_create_x8(name, 0600, \
+ dbg.dbgdir, \
+ &(dbg.dbg_module[id])); \
} while (0)

static int iwm_debugfs_u32_read(void *data, u64 *val)
@@ -423,89 +422,29 @@ static const struct file_operations iwm_debugfs_fw_err_fops = {
.read = iwm_debugfs_fw_err_read,
};

-int iwm_debugfs_init(struct iwm_priv *iwm)
+void iwm_debugfs_init(struct iwm_priv *iwm)
{
- int i, result;
- char devdir[16];
+ int i;

iwm->dbg.rootdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
- result = PTR_ERR(iwm->dbg.rootdir);
- if (!result || IS_ERR(iwm->dbg.rootdir)) {
- if (result == -ENODEV) {
- IWM_ERR(iwm, "DebugFS (CONFIG_DEBUG_FS) not "
- "enabled in kernel config\n");
- result = 0; /* No debugfs support */
- }
- IWM_ERR(iwm, "Couldn't create rootdir: %d\n", result);
- goto error;
- }
-
- snprintf(devdir, sizeof(devdir), "%s", wiphy_name(iwm_to_wiphy(iwm)));
-
- iwm->dbg.devdir = debugfs_create_dir(devdir, iwm->dbg.rootdir);
- result = PTR_ERR(iwm->dbg.devdir);
- if (IS_ERR(iwm->dbg.devdir) && (result != -ENODEV)) {
- IWM_ERR(iwm, "Couldn't create devdir: %d\n", result);
- goto error;
- }
-
+ iwm->dbg.devdir = debugfs_create_dir(wiphy_name(iwm_to_wiphy(iwm)),
+ iwm->dbg.rootdir);
iwm->dbg.dbgdir = debugfs_create_dir("debug", iwm->dbg.devdir);
- result = PTR_ERR(iwm->dbg.dbgdir);
- if (IS_ERR(iwm->dbg.dbgdir) && (result != -ENODEV)) {
- IWM_ERR(iwm, "Couldn't create dbgdir: %d\n", result);
- goto error;
- }
-
iwm->dbg.rxdir = debugfs_create_dir("rx", iwm->dbg.devdir);
- result = PTR_ERR(iwm->dbg.rxdir);
- if (IS_ERR(iwm->dbg.rxdir) && (result != -ENODEV)) {
- IWM_ERR(iwm, "Couldn't create rx dir: %d\n", result);
- goto error;
- }
-
iwm->dbg.txdir = debugfs_create_dir("tx", iwm->dbg.devdir);
- result = PTR_ERR(iwm->dbg.txdir);
- if (IS_ERR(iwm->dbg.txdir) && (result != -ENODEV)) {
- IWM_ERR(iwm, "Couldn't create tx dir: %d\n", result);
- goto error;
- }
-
iwm->dbg.busdir = debugfs_create_dir("bus", iwm->dbg.devdir);
- result = PTR_ERR(iwm->dbg.busdir);
- if (IS_ERR(iwm->dbg.busdir) && (result != -ENODEV)) {
- IWM_ERR(iwm, "Couldn't create bus dir: %d\n", result);
- goto error;
- }
-
- if (iwm->bus_ops->debugfs_init) {
- result = iwm->bus_ops->debugfs_init(iwm, iwm->dbg.busdir);
- if (result < 0) {
- IWM_ERR(iwm, "Couldn't create bus entry: %d\n", result);
- goto error;
- }
- }
-
+ if (iwm->bus_ops->debugfs_init)
+ iwm->bus_ops->debugfs_init(iwm, iwm->dbg.busdir);

iwm->dbg.dbg_level = IWM_DL_NONE;
iwm->dbg.dbg_level_dentry =
debugfs_create_file("level", 0200, iwm->dbg.dbgdir, iwm,
&fops_iwm_dbg_level);
- result = PTR_ERR(iwm->dbg.dbg_level_dentry);
- if (IS_ERR(iwm->dbg.dbg_level_dentry) && (result != -ENODEV)) {
- IWM_ERR(iwm, "Couldn't create dbg_level: %d\n", result);
- goto error;
- }
-

iwm->dbg.dbg_modules = IWM_DM_DEFAULT;
iwm->dbg.dbg_modules_dentry =
debugfs_create_file("modules", 0200, iwm->dbg.dbgdir, iwm,
&fops_iwm_dbg_modules);
- result = PTR_ERR(iwm->dbg.dbg_modules_dentry);
- if (IS_ERR(iwm->dbg.dbg_modules_dentry) && (result != -ENODEV)) {
- IWM_ERR(iwm, "Couldn't create dbg_modules: %d\n", result);
- goto error;
- }

for (i = 0; i < __IWM_DM_NR; i++)
add_dbg_module(iwm->dbg, iwm_debug_module[i].name,
@@ -514,44 +453,15 @@ int iwm_debugfs_init(struct iwm_priv *iwm)
iwm->dbg.txq_dentry = debugfs_create_file("queues", 0200,
iwm->dbg.txdir, iwm,
&iwm_debugfs_txq_fops);
- result = PTR_ERR(iwm->dbg.txq_dentry);
- if (IS_ERR(iwm->dbg.txq_dentry) && (result != -ENODEV)) {
- IWM_ERR(iwm, "Couldn't create tx queue: %d\n", result);
- goto error;
- }
-
iwm->dbg.tx_credit_dentry = debugfs_create_file("credits", 0200,
iwm->dbg.txdir, iwm,
&iwm_debugfs_tx_credit_fops);
- result = PTR_ERR(iwm->dbg.tx_credit_dentry);
- if (IS_ERR(iwm->dbg.tx_credit_dentry) && (result != -ENODEV)) {
- IWM_ERR(iwm, "Couldn't create tx credit: %d\n", result);
- goto error;
- }
-
iwm->dbg.rx_ticket_dentry = debugfs_create_file("tickets", 0200,
iwm->dbg.rxdir, iwm,
&iwm_debugfs_rx_ticket_fops);
- result = PTR_ERR(iwm->dbg.rx_ticket_dentry);
- if (IS_ERR(iwm->dbg.rx_ticket_dentry) && (result != -ENODEV)) {
- IWM_ERR(iwm, "Couldn't create rx ticket: %d\n", result);
- goto error;
- }
-
iwm->dbg.fw_err_dentry = debugfs_create_file("last_fw_err", 0200,
iwm->dbg.dbgdir, iwm,
&iwm_debugfs_fw_err_fops);
- result = PTR_ERR(iwm->dbg.fw_err_dentry);
- if (IS_ERR(iwm->dbg.fw_err_dentry) && (result != -ENODEV)) {
- IWM_ERR(iwm, "Couldn't create last FW err: %d\n", result);
- goto error;
- }
-
-
- return 0;
-
- error:
- return result;
}

void iwm_debugfs_exit(struct iwm_priv *iwm)
diff --git a/drivers/net/wireless/iwmc3200wifi/sdio.c b/drivers/net/wireless/iwmc3200wifi/sdio.c
index 1eafd6d..1acea37 100644
--- a/drivers/net/wireless/iwmc3200wifi/sdio.c
+++ b/drivers/net/wireless/iwmc3200wifi/sdio.c
@@ -366,21 +366,13 @@ static const struct file_operations iwm_debugfs_sdio_fops = {
.read = iwm_debugfs_sdio_read,
};

-static int if_sdio_debugfs_init(struct iwm_priv *iwm, struct dentry *parent_dir)
+static void if_sdio_debugfs_init(struct iwm_priv *iwm, struct dentry *parent_dir)
{
- int result;
struct iwm_sdio_priv *hw = iwm_to_if_sdio(iwm);

hw->cccr_dentry = debugfs_create_file("cccr", 0200,
parent_dir, iwm,
&iwm_debugfs_sdio_fops);
- result = PTR_ERR(hw->cccr_dentry);
- if (IS_ERR(hw->cccr_dentry) && (result != -ENODEV)) {
- IWM_ERR(iwm, "Couldn't create CCCR entry: %d\n", result);
- return result;
- }
-
- return 0;
}

static void if_sdio_debugfs_exit(struct iwm_priv *iwm)
@@ -440,11 +432,7 @@ static int iwm_sdio_probe(struct sdio_func *func,
hw = iwm_private(iwm);
hw->iwm = iwm;

- ret = iwm_debugfs_init(iwm);
- if (ret < 0) {
- IWM_ERR(iwm, "Debugfs registration failed\n");
- goto if_free;
- }
+ iwm_debugfs_init(iwm);

sdio_set_drvdata(func, hw);

@@ -473,7 +461,6 @@ static int iwm_sdio_probe(struct sdio_func *func,
destroy_workqueue(hw->isr_wq);
debugfs_exit:
iwm_debugfs_exit(iwm);
- if_free:
iwm_if_free(iwm);
return ret;
}


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