diff mbox series

[net-next,3/6] net: gianfar: allocate queues with devm

Message ID 20241001212204.308758-4-rosenp@gmail.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series gianfar cleanups | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 9 this patch: 9
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 9 this patch: 9
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn fail Errors and warnings before: 12 this patch: 12
netdev/checkpatch warning CHECK: Lines should not end with a '('
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Rosen Penev Oct. 1, 2024, 9:22 p.m. UTC 
There seems to be a mistake here where free_tx_queue is called on
failure. Just let devm deal with it.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/net/ethernet/freescale/gianfar.c | 38 +++++-------------------
 1 file changed, 7 insertions(+), 31 deletions(-)

Comments

Maxime Chevallier Oct. 2, 2024, 7:25 a.m. UTC | #1 
On Tue,  1 Oct 2024 14:22:01 -0700
Rosen Penev <rosenp@gmail.com> wrote:

> There seems to be a mistake here where free_tx_queue is called on
> failure. Just let devm deal with it.

Good catch, this looks good to me.

Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>

Maxime
Claudiu Manoil Oct. 4, 2024, 6:31 a.m. UTC | #2 
> -----Original Message-----
> From: Maxime Chevallier <maxime.chevallier@bootlin.com>
> Sent: Wednesday, October 2, 2024 10:25 AM
[...]
> 
> On Tue,  1 Oct 2024 14:22:01 -0700
> Rosen Penev <rosenp@gmail.com> wrote:
> 
> > There seems to be a mistake here where free_tx_queue is called on
> > failure. Just let devm deal with it.
> 
> Good catch, this looks good to me.
> 

I like your enthusiasm, but there's nothing to catch here.
kfree() does nothing to NULL objects, however the 'constructor' allocates an
array of objects so free_tx_queues() has to iterate over all objects, to free those
allocated before failure.

I don't have a strong opinion regarding the usage of devm_*() API to allocate resources
at device probing time, it saves some lines of code. However I see this as bringing limited
benefits for simple cases like device probe()/remove(), especially when converting old drivers
like this one. And there's also the risk of falling into the trap of thinking that devm_*() takes
care of everything.

-Claudiu
diff mbox series

Patch

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 9f0824f0b2d1..66818d63cced 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -412,8 +412,8 @@  static int gfar_alloc_tx_queues(struct gfar_private *priv)
 	int i;
 
 	for (i = 0; i < priv->num_tx_queues; i++) {
-		priv->tx_queue[i] = kzalloc(sizeof(struct gfar_priv_tx_q),
-					    GFP_KERNEL);
+		priv->tx_queue[i] = devm_kzalloc(
+			priv->dev, sizeof(struct gfar_priv_tx_q), GFP_KERNEL);
 		if (!priv->tx_queue[i])
 			return -ENOMEM;
 
@@ -430,8 +430,8 @@  static int gfar_alloc_rx_queues(struct gfar_private *priv)
 	int i;
 
 	for (i = 0; i < priv->num_rx_queues; i++) {
-		priv->rx_queue[i] = kzalloc(sizeof(struct gfar_priv_rx_q),
-					    GFP_KERNEL);
+		priv->rx_queue[i] = devm_kzalloc(
+			priv->dev, sizeof(struct gfar_priv_rx_q), GFP_KERNEL);
 		if (!priv->rx_queue[i])
 			return -ENOMEM;
 
@@ -441,22 +441,6 @@  static int gfar_alloc_rx_queues(struct gfar_private *priv)
 	return 0;
 }
 
-static void gfar_free_tx_queues(struct gfar_private *priv)
-{
-	int i;
-
-	for (i = 0; i < priv->num_tx_queues; i++)
-		kfree(priv->tx_queue[i]);
-}
-
-static void gfar_free_rx_queues(struct gfar_private *priv)
-{
-	int i;
-
-	for (i = 0; i < priv->num_rx_queues; i++)
-		kfree(priv->rx_queue[i]);
-}
-
 static void unmap_group_regs(struct gfar_private *priv)
 {
 	int i;
@@ -685,16 +669,16 @@  static int gfar_of_init(struct platform_device *ofdev, struct net_device **pdev)
 
 	err = gfar_alloc_tx_queues(priv);
 	if (err)
-		goto tx_alloc_failed;
+		return err;
 
 	err = gfar_alloc_rx_queues(priv);
 	if (err)
-		goto rx_alloc_failed;
+		return err;
 
 	err = of_property_read_string(np, "model", &model);
 	if (err) {
 		pr_err("Device model property missing, aborting\n");
-		goto rx_alloc_failed;
+		return err;
 	}
 
 	/* Init Rx queue filer rule set linked list */
@@ -803,10 +787,6 @@  static int gfar_of_init(struct platform_device *ofdev, struct net_device **pdev)
 
 err_grp_init:
 	unmap_group_regs(priv);
-rx_alloc_failed:
-	gfar_free_rx_queues(priv);
-tx_alloc_failed:
-	gfar_free_tx_queues(priv);
 	return err;
 }
 
@@ -3345,8 +3325,6 @@  static int gfar_probe(struct platform_device *ofdev)
 	if (of_phy_is_fixed_link(np))
 		of_phy_deregister_fixed_link(np);
 	unmap_group_regs(priv);
-	gfar_free_rx_queues(priv);
-	gfar_free_tx_queues(priv);
 	of_node_put(priv->phy_node);
 	of_node_put(priv->tbi_node);
 	return err;
@@ -3366,8 +3344,6 @@  static void gfar_remove(struct platform_device *ofdev)
 		of_phy_deregister_fixed_link(np);
 
 	unmap_group_regs(priv);
-	gfar_free_rx_queues(priv);
-	gfar_free_tx_queues(priv);
 }
 
 #ifdef CONFIG_PM