[PATCH] drivers/macintosh/smu.c: improve error handling

From: Julia Lawall
Date: Mon Jun 23 2008 - 14:15:15 EST


From: Julia Lawall <julia@xxxxxxx>

This patch makes two changes:
* As noted by Akinobu Mita in patch
b1fceac2b9e04d278316b2faddf276015fc06e3b, alloc_bootmem never returns NULL
and always returns a zeroed region of memory. Thus the error checking code
and memset after the call to alloc_bootmem are not necessary.
* The old error handling code consisted of setting a global variable to
NULL and returning an error code, which could cause previously allocated
resources never to be freed. The patch adds calls to appropriate resource
deallocation functions.

drivers/macintosh/smu.c | 34 +++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)

Signed-off-by: Julia Lawall <julia@xxxxxxx>
---

diff -u -p a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
--- a/drivers/macintosh/smu.c
+++ b/drivers/macintosh/smu.c
@@ -474,6 +474,7 @@ int __init smu_init (void)
{
struct device_node *np;
const u32 *data;
+ int ret = 0;

np = of_find_node_by_type(NULL, "smu");
if (np == NULL)
@@ -483,16 +484,11 @@ int __init smu_init (void)

if (smu_cmdbuf_abs == 0) {
printk(KERN_ERR "SMU: Command buffer not allocated !\n");
- of_node_put(np);
- return -EINVAL;
+ ret = -EINVAL;
+ goto fail_np;
}

smu = alloc_bootmem(sizeof(struct smu_device));
- if (smu == NULL) {
- of_node_put(np);
- return -ENOMEM;
- }
- memset(smu, 0, sizeof(*smu));

spin_lock_init(&smu->lock);
INIT_LIST_HEAD(&smu->cmd_list);
@@ -510,14 +506,14 @@ int __init smu_init (void)
smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
if (smu->db_node == NULL) {
printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
- goto fail;
+ ret = -ENXIO;
+ goto fail_bootmem;
}
data = of_get_property(smu->db_node, "reg", NULL);
if (data == NULL) {
- of_node_put(smu->db_node);
- smu->db_node = NULL;
printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
- goto fail;
+ ret = -ENXIO;
+ goto fail_db_node;
}

/* Current setup has one doorbell GPIO that does both doorbell
@@ -551,7 +547,8 @@ int __init smu_init (void)
smu->db_buf = ioremap(0x8000860c, 0x1000);
if (smu->db_buf == NULL) {
printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
- goto fail;
+ ret = -ENXIO;
+ goto fail_msg_node;
}

/* U3 has an issue with NAP mode when issuing SMU commands */
@@ -562,10 +559,17 @@ int __init smu_init (void)
sys_ctrler = SYS_CTRLER_SMU;
return 0;

- fail:
+fail_msg_node:
+ if (smu->msg_node)
+ of_node_put(smu->msg_node);
+fail_db_node:
+ of_node_put(smu->db_node);
+fail_bootmem:
+ free_bootmem((unsigned long)smu, sizeof(struct smu_device));
smu = NULL;
- return -ENXIO;
-
+fail_np:
+ of_node_put(np);
+ return ret;
}


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