A number of variables don't need to be initialized.
In a couple of cases where we loop on a list of runtimes, the code
handling of the 'bus' variable leads to warnings that it may not be
initialized. Add a specific error case to trap such cases.
Signed-off-by: Pierre-Louis Bossart <[email protected]>
---
drivers/soundwire/stream.c | 64 ++++++++++++++++++++++----------------
1 file changed, 38 insertions(+), 26 deletions(-)
diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
index 75b9ad1fb1a6..8d6c13528b68 100644
--- a/drivers/soundwire/stream.c
+++ b/drivers/soundwire/stream.c
@@ -369,7 +369,7 @@ static int sdw_enable_disable_master_ports(struct sdw_master_runtime *m_rt,
static int sdw_enable_disable_ports(struct sdw_master_runtime *m_rt, bool en)
{
struct sdw_port_runtime *s_port, *m_port;
- struct sdw_slave_runtime *s_rt = NULL;
+ struct sdw_slave_runtime *s_rt;
int ret = 0;
/* Enable/Disable Slave port(s) */
@@ -417,7 +417,7 @@ static int sdw_prep_deprep_slave_ports(struct sdw_bus *bus,
struct sdw_port_runtime *p_rt,
bool prep)
{
- struct completion *port_ready = NULL;
+ struct completion *port_ready;
struct sdw_dpn_prop *dpn_prop;
struct sdw_prepare_ch prep_ch;
unsigned int time_left;
@@ -537,7 +537,7 @@ static int sdw_prep_deprep_master_ports(struct sdw_master_runtime *m_rt,
*/
static int sdw_prep_deprep_ports(struct sdw_master_runtime *m_rt, bool prep)
{
- struct sdw_slave_runtime *s_rt = NULL;
+ struct sdw_slave_runtime *s_rt;
struct sdw_port_runtime *p_rt;
int ret = 0;
@@ -605,7 +605,7 @@ static int sdw_notify_config(struct sdw_master_runtime *m_rt)
*/
static int sdw_program_params(struct sdw_bus *bus)
{
- struct sdw_master_runtime *m_rt = NULL;
+ struct sdw_master_runtime *m_rt;
int ret = 0;
list_for_each_entry(m_rt, &bus->m_rt_list, bus_node) {
@@ -642,8 +642,8 @@ static int sdw_bank_switch(struct sdw_bus *bus, int m_rt_count)
int col_index, row_index;
bool multi_link;
struct sdw_msg *wr_msg;
- u8 *wbuf = NULL;
- int ret = 0;
+ u8 *wbuf;
+ int ret;
u16 addr;
wr_msg = kzalloc(sizeof(*wr_msg), GFP_KERNEL);
@@ -741,9 +741,9 @@ static int sdw_ml_sync_bank_switch(struct sdw_bus *bus)
static int do_bank_switch(struct sdw_stream_runtime *stream)
{
- struct sdw_master_runtime *m_rt = NULL;
+ struct sdw_master_runtime *m_rt;
const struct sdw_master_ops *ops;
- struct sdw_bus *bus = NULL;
+ struct sdw_bus *bus;
bool multi_link = false;
int ret = 0;
@@ -886,7 +886,7 @@ static struct sdw_master_runtime
*sdw_find_master_rt(struct sdw_bus *bus,
struct sdw_stream_runtime *stream)
{
- struct sdw_master_runtime *m_rt = NULL;
+ struct sdw_master_runtime *m_rt;
/* Retrieve Bus handle if already available */
list_for_each_entry(m_rt, &stream->master_list, stream_node) {
@@ -955,7 +955,7 @@ static struct sdw_slave_runtime
struct sdw_stream_config *stream_config,
struct sdw_stream_runtime *stream)
{
- struct sdw_slave_runtime *s_rt = NULL;
+ struct sdw_slave_runtime *s_rt;
s_rt = kzalloc(sizeof(*s_rt), GFP_KERNEL);
if (!s_rt)
@@ -1261,7 +1261,7 @@ int sdw_stream_add_master(struct sdw_bus *bus,
unsigned int num_ports,
struct sdw_stream_runtime *stream)
{
- struct sdw_master_runtime *m_rt = NULL;
+ struct sdw_master_runtime *m_rt;
int ret;
mutex_lock(&bus->bus_lock);
@@ -1428,7 +1428,7 @@ struct sdw_dpn_prop *sdw_get_slave_dpn_prop(struct sdw_slave *slave,
*/
static void sdw_acquire_bus_lock(struct sdw_stream_runtime *stream)
{
- struct sdw_master_runtime *m_rt = NULL;
+ struct sdw_master_runtime *m_rt;
struct sdw_bus *bus = NULL;
/* Iterate for all Master(s) in Master list */
@@ -1462,9 +1462,9 @@ static void sdw_release_bus_lock(struct sdw_stream_runtime *stream)
static int _sdw_prepare_stream(struct sdw_stream_runtime *stream)
{
- struct sdw_master_runtime *m_rt = NULL;
+ struct sdw_master_runtime *m_rt;
struct sdw_bus *bus = NULL;
- struct sdw_master_prop *prop = NULL;
+ struct sdw_master_prop *prop;
struct sdw_bus_params params;
int ret;
@@ -1493,6 +1493,11 @@ static int _sdw_prepare_stream(struct sdw_stream_runtime *stream)
}
}
+ if (!bus) {
+ pr_err("Configuration error in %s\n", __func__);
+ return -EINVAL;
+ }
+
ret = do_bank_switch(stream);
if (ret < 0) {
dev_err(bus->dev, "Bank switch failed: %d\n", ret);
@@ -1549,7 +1554,7 @@ EXPORT_SYMBOL(sdw_prepare_stream);
static int _sdw_enable_stream(struct sdw_stream_runtime *stream)
{
- struct sdw_master_runtime *m_rt = NULL;
+ struct sdw_master_runtime *m_rt;
struct sdw_bus *bus = NULL;
int ret;
@@ -1573,6 +1578,11 @@ static int _sdw_enable_stream(struct sdw_stream_runtime *stream)
}
}
+ if (!bus) {
+ pr_err("Configuration error in %s\n", __func__);
+ return -EINVAL;
+ }
+
ret = do_bank_switch(stream);
if (ret < 0) {
dev_err(bus->dev, "Bank switch failed: %d\n", ret);
@@ -1592,7 +1602,7 @@ static int _sdw_enable_stream(struct sdw_stream_runtime *stream)
*/
int sdw_enable_stream(struct sdw_stream_runtime *stream)
{
- int ret = 0;
+ int ret;
if (!stream) {
pr_err("SoundWire: Handle not found for stream\n");
@@ -1612,12 +1622,12 @@ EXPORT_SYMBOL(sdw_enable_stream);
static int _sdw_disable_stream(struct sdw_stream_runtime *stream)
{
- struct sdw_master_runtime *m_rt = NULL;
- struct sdw_bus *bus = NULL;
+ struct sdw_master_runtime *m_rt;
int ret;
list_for_each_entry(m_rt, &stream->master_list, stream_node) {
- bus = m_rt->bus;
+ struct sdw_bus *bus = m_rt->bus;
+
/* Disable port(s) */
ret = sdw_enable_disable_ports(m_rt, false);
if (ret < 0) {
@@ -1628,7 +1638,8 @@ static int _sdw_disable_stream(struct sdw_stream_runtime *stream)
stream->state = SDW_STREAM_DISABLED;
list_for_each_entry(m_rt, &stream->master_list, stream_node) {
- bus = m_rt->bus;
+ struct sdw_bus *bus = m_rt->bus;
+
/* Program params */
ret = sdw_program_params(bus);
if (ret < 0) {
@@ -1639,13 +1650,14 @@ static int _sdw_disable_stream(struct sdw_stream_runtime *stream)
ret = do_bank_switch(stream);
if (ret < 0) {
- dev_err(bus->dev, "Bank switch failed: %d\n", ret);
+ pr_err("Bank switch failed: %d\n", ret);
return ret;
}
/* make sure alternate bank (previous current) is also disabled */
list_for_each_entry(m_rt, &stream->master_list, stream_node) {
- bus = m_rt->bus;
+ struct sdw_bus *bus = m_rt->bus;
+
/* Disable port(s) */
ret = sdw_enable_disable_ports(m_rt, false);
if (ret < 0) {
@@ -1666,7 +1678,7 @@ static int _sdw_disable_stream(struct sdw_stream_runtime *stream)
*/
int sdw_disable_stream(struct sdw_stream_runtime *stream)
{
- int ret = 0;
+ int ret;
if (!stream) {
pr_err("SoundWire: Handle not found for stream\n");
@@ -1686,8 +1698,8 @@ EXPORT_SYMBOL(sdw_disable_stream);
static int _sdw_deprepare_stream(struct sdw_stream_runtime *stream)
{
- struct sdw_master_runtime *m_rt = NULL;
- struct sdw_bus *bus = NULL;
+ struct sdw_master_runtime *m_rt;
+ struct sdw_bus *bus;
int ret = 0;
list_for_each_entry(m_rt, &stream->master_list, stream_node) {
@@ -1725,7 +1737,7 @@ static int _sdw_deprepare_stream(struct sdw_stream_runtime *stream)
*/
int sdw_deprepare_stream(struct sdw_stream_runtime *stream)
{
- int ret = 0;
+ int ret;
if (!stream) {
pr_err("SoundWire: Handle not found for stream\n");
--
2.20.1
On 2019-08-06 02:55, Pierre-Louis Bossart wrote:
> @@ -1493,6 +1493,11 @@ static int _sdw_prepare_stream(struct sdw_stream_runtime *stream)
> }
> }
>
> + if (!bus) {
> + pr_err("Configuration error in %s\n", __func__);
> + return -EINVAL;
> + }
> +
This should probably be located in separate path - not at all an
initialization removal.
> @@ -1573,6 +1578,11 @@ static int _sdw_enable_stream(struct sdw_stream_runtime *stream)
> }
> }
>
> + if (!bus) {
> + pr_err("Configuration error in %s\n", __func__);
> + return -EINVAL;
> + }
> +
Same here.
> @@ -1639,13 +1650,14 @@ static int _sdw_disable_stream(struct sdw_stream_runtime *stream)
>
> ret = do_bank_switch(stream);
> if (ret < 0) {
> - dev_err(bus->dev, "Bank switch failed: %d\n", ret);
> + pr_err("Bank switch failed: %d\n", ret);
> return ret;
> }
Here too.
I might have missed something though I bet you got my point.
On 8/6/19 10:31 AM, Cezary Rojewski wrote:
> On 2019-08-06 02:55, Pierre-Louis Bossart wrote:
>> @@ -1493,6 +1493,11 @@ static int _sdw_prepare_stream(struct
>> sdw_stream_runtime *stream)
>> }
>> }
>> + if (!bus) {
>> + pr_err("Configuration error in %s\n", __func__);
>> + return -EINVAL;
>> + }
>> +
>
> This should probably be located in separate path - not at all an
> initialization removal.
It's a consequence of the initialization removal: because we are
removing the default init, there is a risk that the loop just before do
not set it, so it's required to trap the case where the variable in not
initialized.
>
>> @@ -1573,6 +1578,11 @@ static int _sdw_enable_stream(struct
>> sdw_stream_runtime *stream)
>> }
>> }
>> + if (!bus) {
>> + pr_err("Configuration error in %s\n", __func__);
>> + return -EINVAL;
>> + }
>> +
>
> Same here.
same reply
>
>> @@ -1639,13 +1650,14 @@ static int _sdw_disable_stream(struct
>> sdw_stream_runtime *stream)
>> ret = do_bank_switch(stream);
>> if (ret < 0) {
>> - dev_err(bus->dev, "Bank switch failed: %d\n", ret);
>> + pr_err("Bank switch failed: %d\n", ret);
>> return ret;
>> }
>
> Here too.
no, same thing, the bus variable is initialized in loops so tools will
report a possible path where bus->dev is an invalid dereference.
> I might have missed something though I bet you got my point.