raspi/linux
1
0
Fork 1
mirror of https://github.com/raspberrypi/linux.git synced 2025-12-06 01:49:46 +00:00
Code Issues Projects Releases Wiki Activity

net: ethernet: ti: netcp: Standardize knav_dma_open_channel to return NULL on error

Browse Source 
[ Upstream commit 90a88306eb ]

Make knav_dma_open_channel consistently return NULL on error instead
of ERR_PTR. Currently the header include/linux/soc/ti/knav_dma.h
returns NULL when the driver is disabled, but the driver
implementation does not even return NULL or ERR_PTR on failure,
causing inconsistency in the users. This results in a crash in
netcp_free_navigator_resources as followed (trimmed):

Unhandled fault: alignment exception (0x221) at 0xfffffff2
[fffffff2] *pgd=80000800207003, *pmd=82ffda003, *pte=00000000
Internal error: : 221 [#1] SMP ARM
Modules linked in:
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.17.0-rc7 #1 NONE
Hardware name: Keystone
PC is at knav_dma_close_channel+0x30/0x19c
LR is at netcp_free_navigator_resources+0x2c/0x28c

[... TRIM...]

Call trace:
 knav_dma_close_channel from netcp_free_navigator_resources+0x2c/0x28c
 netcp_free_navigator_resources from netcp_ndo_open+0x430/0x46c
 netcp_ndo_open from __dev_open+0x114/0x29c
 __dev_open from __dev_change_flags+0x190/0x208
 __dev_change_flags from netif_change_flags+0x1c/0x58
 netif_change_flags from dev_change_flags+0x38/0xa0
 dev_change_flags from ip_auto_config+0x2c4/0x11f0
 ip_auto_config from do_one_initcall+0x58/0x200
 do_one_initcall from kernel_init_freeable+0x1cc/0x238
 kernel_init_freeable from kernel_init+0x1c/0x12c
 kernel_init from ret_from_fork+0x14/0x38
[... TRIM...]

Standardize the error handling by making the function return NULL on
all error conditions. The API is used in just the netcp_core.c so the
impact is limited.

Note, this change, in effect reverts commit 5b6cb43b4d ("net:
ethernet: ti: netcp_core: return error while dma channel open issue"),
but provides a less error prone implementation.

Suggested-by: Simon Horman <horms@kernel.org>
Suggested-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20251103162811.3730055-1-nm@ti.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Nishanth Menon
2025-11-03 10:28:11 -06:00
committed by Greg Kroah-Hartman
parent b712f234a7
commit f9608637ec
2 changed files with 12 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/net/ethernet/ti/netcp_core.c
View File

@@ -1338,10 +1338,10 @@ int netcp_txpipe_open(struct netcp_tx_pipe *tx_pipe)
tx_pipe->dma_channel = knav_dma_open_channel(dev,
tx_pipe->dma_chan_name, &config);
if (IS_ERR(tx_pipe->dma_channel)) {
if (!tx_pipe->dma_channel) {
dev_err(dev, "failed opening tx chan(%s)\n",
tx_pipe->dma_chan_name);
ret = PTR_ERR(tx_pipe->dma_channel);
ret = -EINVAL;
goto err;
}
@@ -1359,7 +1359,7 @@ int netcp_txpipe_open(struct netcp_tx_pipe *tx_pipe)
return 0;
err:
if (!IS_ERR_OR_NULL(tx_pipe->dma_channel))
if (tx_pipe->dma_channel)
knav_dma_close_channel(tx_pipe->dma_channel);
tx_pipe->dma_channel = NULL;
return ret;
@@ -1678,10 +1678,10 @@ static int netcp_setup_navigator_resources(struct net_device *ndev)
netcp->rx_channel = knav_dma_open_channel(netcp->netcp_device->device,
netcp->dma_chan_name, &config);
if (IS_ERR(netcp->rx_channel)) {
if (!netcp->rx_channel) {
dev_err(netcp->ndev_dev, "failed opening rx chan(%s\n",
netcp->dma_chan_name);
ret = PTR_ERR(netcp->rx_channel);
ret = -EINVAL;
goto fail;
}

14
drivers/soc/ti/knav_dma.c
View File

@@ -402,7 +402,7 @@ static int of_channel_match_helper(struct device_node *np, const char *name,
* @name: slave channel name
* @config: dma configuration parameters
*
* Returns pointer to appropriate DMA channel on success or error.
* Return: Pointer to appropriate DMA channel on success or NULL on error.
*/
void *knav_dma_open_channel(struct device *dev, const char *name,
struct knav_dma_cfg *config)
@@ -414,13 +414,13 @@ void *knav_dma_open_channel(struct device *dev, const char *name,
if (!kdev) {
pr_err("keystone-navigator-dma driver not registered\n");
return (void *)-EINVAL;
return NULL;
}
chan_num = of_channel_match_helper(dev->of_node, name, &instance);
if (chan_num < 0) {
dev_err(kdev->dev, "No DMA instance with name %s\n", name);
return (void *)-EINVAL;
return NULL;
}
dev_dbg(kdev->dev, "initializing %s channel %d from DMA %s\n",
@@ -431,7 +431,7 @@ void *knav_dma_open_channel(struct device *dev, const char *name,
if (config->direction != DMA_MEM_TO_DEV &&
config->direction != DMA_DEV_TO_MEM) {
dev_err(kdev->dev, "bad direction\n");
return (void *)-EINVAL;
return NULL;
}
/* Look for correct dma instance */
@@ -443,7 +443,7 @@ void *knav_dma_open_channel(struct device *dev, const char *name,
}
if (!dma) {
dev_err(kdev->dev, "No DMA instance with name %s\n", instance);
return (void *)-EINVAL;
return NULL;
}
/* Look for correct dma channel from dma instance */
@@ -463,14 +463,14 @@ void *knav_dma_open_channel(struct device *dev, const char *name,
if (!chan) {
dev_err(kdev->dev, "channel %d is not in DMA %s\n",
chan_num, instance);
return (void *)-EINVAL;
return NULL;
}
if (atomic_read(&chan->ref_count) >= 1) {
if (!check_config(chan, config)) {
dev_err(kdev->dev, "channel %d config miss-match\n",
chan_num);
return (void *)-EINVAL;
return NULL;
}
}