[PATCH v1] dmaengine: acpi: Drop double check for ACPI companion device

[PATCH v1] dmaengine: acpi: Drop double check for ACPI companion device

[Andy Shevchenko]

acpi_dev_get_resources() does perform the NULL pointer check against
ACPI companion device which is given as function parameter. Thus,
there is no need to duplicate this check in the caller.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/dma/acpi-dma.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c
index 8a05db3343d3..4aee511578ad 100644
--- a/drivers/dma/acpi-dma.c
+++ b/drivers/dma/acpi-dma.c
@@ -358,19 +358,12 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
 {
 	struct acpi_dma_parser_data pdata;
 	struct acpi_dma_spec *dma_spec = &pdata.dma_spec;
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 	struct list_head resource_list;
-	struct acpi_device *adev;
 	struct acpi_dma *adma;
 	struct dma_chan *chan = NULL;
 	int found;
-
-	/* Check if the device was enumerated by ACPI */
-	if (!dev)
-		return ERR_PTR(-ENODEV);
-
-	adev = ACPI_COMPANION(dev);
-	if (!adev)
-		return ERR_PTR(-ENODEV);
+	int ret;
 
 	memset(&pdata, 0, sizeof(pdata));
 	pdata.index = index;
@@ -380,9 +373,11 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
 	dma_spec->slave_id = -1;
 
 	INIT_LIST_HEAD(&resource_list);
-	acpi_dev_get_resources(adev, &resource_list,
-			acpi_dma_parse_fixed_dma, &pdata);
+	ret = acpi_dev_get_resources(adev, &resource_list,
+				     acpi_dma_parse_fixed_dma, &pdata);
 	acpi_dev_free_resource_list(&resource_list);
+	if (ret < 0)
+		return ret;
 
 	if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0)
 		return ERR_PTR(-ENODEV);
-- 
2.27.0

Re: [PATCH v1] dmaengine: acpi: Drop double check for ACPI companion device

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 3667 bytes --]

Hi Andy,

I love your patch! Perhaps something to improve:

[auto build test WARNING on slave-dma/next]
[also build test WARNING on linus/master v5.8-rc2 next-20200622]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Andy-Shevchenko/dmaengine-acpi-Drop-double-check-for-ACPI-companion-device/20200622-170946
base:   https://git.kernel.org/pub/scm/linux/kernel/git/vkoul/slave-dma.git next
config: i386-randconfig-s002-20200622 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-13) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.2-dirty
        # save the attached .config to linux build tree
        make W=1 C=1 ARCH=i386 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)

>> drivers/dma/acpi-dma.c:380:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected struct dma_chan * @@     got int [assigned] ret @@
>> drivers/dma/acpi-dma.c:380:24: sparse:     expected struct dma_chan *
>> drivers/dma/acpi-dma.c:380:24: sparse:     got int [assigned] ret

vim +380 drivers/dma/acpi-dma.c

   347	
   348	/**
   349	 * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel
   350	 * @dev:	struct device to get DMA request from
   351	 * @index:	index of FixedDMA descriptor for @dev
   352	 *
   353	 * Return:
   354	 * Pointer to appropriate dma channel on success or an error pointer.
   355	 */
   356	struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
   357			size_t index)
   358	{
   359		struct acpi_dma_parser_data pdata;
   360		struct acpi_dma_spec *dma_spec = &pdata.dma_spec;
   361		struct acpi_device *adev = ACPI_COMPANION(dev);
   362		struct list_head resource_list;
   363		struct acpi_dma *adma;
   364		struct dma_chan *chan = NULL;
   365		int found;
   366		int ret;
   367	
   368		memset(&pdata, 0, sizeof(pdata));
   369		pdata.index = index;
   370	
   371		/* Initial values for the request line and channel */
   372		dma_spec->chan_id = -1;
   373		dma_spec->slave_id = -1;
   374	
   375		INIT_LIST_HEAD(&resource_list);
   376		ret = acpi_dev_get_resources(adev, &resource_list,
   377					     acpi_dma_parse_fixed_dma, &pdata);
   378		acpi_dev_free_resource_list(&resource_list);
   379		if (ret < 0)
 > 380			return ret;
   381	
   382		if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0)
   383			return ERR_PTR(-ENODEV);
   384	
   385		mutex_lock(&acpi_dma_lock);
   386	
   387		list_for_each_entry(adma, &acpi_dma_list, dma_controllers) {
   388			/*
   389			 * We are not going to call translation function if slave_id
   390			 * doesn't fall to the request range.
   391			 */
   392			found = acpi_dma_update_dma_spec(adma, dma_spec);
   393			if (found < 0)
   394				continue;
   395			chan = adma->acpi_dma_xlate(dma_spec, adma);
   396			/*
   397			 * Try to get a channel only from the DMA controller that
   398			 * matches the slave_id. See acpi_dma_update_dma_spec()
   399			 * description for the details.
   400			 */
   401			if (found > 0 || chan)
   402				break;
   403		}
   404	
   405		mutex_unlock(&acpi_dma_lock);
   406		return chan ? chan : ERR_PTR(-EPROBE_DEFER);
   407	}
   408	EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index);
   409	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 35028 bytes --]

Re: [PATCH v1] dmaengine: acpi: Drop double check for ACPI companion device

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 3765 bytes --]

Hi Andy,

I love your patch! Perhaps something to improve:

[auto build test WARNING on slave-dma/next]
[also build test WARNING on linus/master v5.8-rc2 next-20200622]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Andy-Shevchenko/dmaengine-acpi-Drop-double-check-for-ACPI-companion-device/20200622-170946
base:   https://git.kernel.org/pub/scm/linux/kernel/git/vkoul/slave-dma.git next
config: x86_64-randconfig-s022-20200622 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-13) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.2-dirty
        # save the attached .config to linux build tree
        make W=1 C=1 ARCH=x86_64 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)

   drivers/dma/acpi-dma.c:380:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected struct dma_chan * @@     got int [assigned] ret @@
   drivers/dma/acpi-dma.c:380:24: sparse:     expected struct dma_chan *
   drivers/dma/acpi-dma.c:380:24: sparse:     got int [assigned] ret
>> drivers/dma/acpi-dma.c:380:24: sparse: sparse: non size-preserving integer to pointer cast

vim +380 drivers/dma/acpi-dma.c

   347	
   348	/**
   349	 * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel
   350	 * @dev:	struct device to get DMA request from
   351	 * @index:	index of FixedDMA descriptor for @dev
   352	 *
   353	 * Return:
   354	 * Pointer to appropriate dma channel on success or an error pointer.
   355	 */
   356	struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
   357			size_t index)
   358	{
   359		struct acpi_dma_parser_data pdata;
   360		struct acpi_dma_spec *dma_spec = &pdata.dma_spec;
   361		struct acpi_device *adev = ACPI_COMPANION(dev);
   362		struct list_head resource_list;
   363		struct acpi_dma *adma;
   364		struct dma_chan *chan = NULL;
   365		int found;
   366		int ret;
   367	
   368		memset(&pdata, 0, sizeof(pdata));
   369		pdata.index = index;
   370	
   371		/* Initial values for the request line and channel */
   372		dma_spec->chan_id = -1;
   373		dma_spec->slave_id = -1;
   374	
   375		INIT_LIST_HEAD(&resource_list);
   376		ret = acpi_dev_get_resources(adev, &resource_list,
   377					     acpi_dma_parse_fixed_dma, &pdata);
   378		acpi_dev_free_resource_list(&resource_list);
   379		if (ret < 0)
 > 380			return ret;
   381	
   382		if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0)
   383			return ERR_PTR(-ENODEV);
   384	
   385		mutex_lock(&acpi_dma_lock);
   386	
   387		list_for_each_entry(adma, &acpi_dma_list, dma_controllers) {
   388			/*
   389			 * We are not going to call translation function if slave_id
   390			 * doesn't fall to the request range.
   391			 */
   392			found = acpi_dma_update_dma_spec(adma, dma_spec);
   393			if (found < 0)
   394				continue;
   395			chan = adma->acpi_dma_xlate(dma_spec, adma);
   396			/*
   397			 * Try to get a channel only from the DMA controller that
   398			 * matches the slave_id. See acpi_dma_update_dma_spec()
   399			 * description for the details.
   400			 */
   401			if (found > 0 || chan)
   402				break;
   403		}
   404	
   405		mutex_unlock(&acpi_dma_lock);
   406		return chan ? chan : ERR_PTR(-EPROBE_DEFER);
   407	}
   408	EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index);
   409	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 33885 bytes --]

Re: [PATCH v1] dmaengine: acpi: Drop double check for ACPI companion device

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 3482 bytes --]

Hi Andy,

I love your patch! Perhaps something to improve:

[auto build test WARNING on slave-dma/next]
[also build test WARNING on linus/master v5.8-rc2 next-20200622]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Andy-Shevchenko/dmaengine-acpi-Drop-double-check-for-ACPI-companion-device/20200622-170946
base:   https://git.kernel.org/pub/scm/linux/kernel/git/vkoul/slave-dma.git next
config: i386-randconfig-a006-20200622 (attached as .config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce (this is a W=1 build):
        # save the attached .config to linux build tree
        make W=1 ARCH=i386 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>, old ones prefixed by <<):

drivers/dma/acpi-dma.c: In function 'acpi_dma_request_slave_chan_by_index':
>> drivers/dma/acpi-dma.c:380:10: warning: return makes pointer from integer without a cast [-Wint-conversion]
return ret;
^~~

vim +380 drivers/dma/acpi-dma.c

   347	
   348	/**
   349	 * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel
   350	 * @dev:	struct device to get DMA request from
   351	 * @index:	index of FixedDMA descriptor for @dev
   352	 *
   353	 * Return:
   354	 * Pointer to appropriate dma channel on success or an error pointer.
   355	 */
   356	struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
   357			size_t index)
   358	{
   359		struct acpi_dma_parser_data pdata;
   360		struct acpi_dma_spec *dma_spec = &pdata.dma_spec;
   361		struct acpi_device *adev = ACPI_COMPANION(dev);
   362		struct list_head resource_list;
   363		struct acpi_dma *adma;
   364		struct dma_chan *chan = NULL;
   365		int found;
   366		int ret;
   367	
   368		memset(&pdata, 0, sizeof(pdata));
   369		pdata.index = index;
   370	
   371		/* Initial values for the request line and channel */
   372		dma_spec->chan_id = -1;
   373		dma_spec->slave_id = -1;
   374	
   375		INIT_LIST_HEAD(&resource_list);
   376		ret = acpi_dev_get_resources(adev, &resource_list,
   377					     acpi_dma_parse_fixed_dma, &pdata);
   378		acpi_dev_free_resource_list(&resource_list);
   379		if (ret < 0)
 > 380			return ret;
   381	
   382		if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0)
   383			return ERR_PTR(-ENODEV);
   384	
   385		mutex_lock(&acpi_dma_lock);
   386	
   387		list_for_each_entry(adma, &acpi_dma_list, dma_controllers) {
   388			/*
   389			 * We are not going to call translation function if slave_id
   390			 * doesn't fall to the request range.
   391			 */
   392			found = acpi_dma_update_dma_spec(adma, dma_spec);
   393			if (found < 0)
   394				continue;
   395			chan = adma->acpi_dma_xlate(dma_spec, adma);
   396			/*
   397			 * Try to get a channel only from the DMA controller that
   398			 * matches the slave_id. See acpi_dma_update_dma_spec()
   399			 * description for the details.
   400			 */
   401			if (found > 0 || chan)
   402				break;
   403		}
   404	
   405		mutex_unlock(&acpi_dma_lock);
   406		return chan ? chan : ERR_PTR(-EPROBE_DEFER);
   407	}
   408	EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index);
   409	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 33330 bytes --]

Re: [PATCH v1] dmaengine: acpi: Drop double check for ACPI companion device

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 3861 bytes --]

Hi Andy,

I love your patch! Perhaps something to improve:

[auto build test WARNING on slave-dma/next]
[also build test WARNING on linus/master v5.8-rc2 next-20200622]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Andy-Shevchenko/dmaengine-acpi-Drop-double-check-for-ACPI-companion-device/20200622-170946
base:   https://git.kernel.org/pub/scm/linux/kernel/git/vkoul/slave-dma.git next
config: arm64-randconfig-r025-20200622 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 1d4c87335d5236ea1f35937e1014980ba961ae34)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>, old ones prefixed by <<):

>> drivers/dma/acpi-dma.c:380:10: warning: incompatible integer to pointer conversion returning 'int' from a function with result type 'struct dma_chan *' [-Wint-conversion]
return ret;
^~~
1 warning generated.

vim +380 drivers/dma/acpi-dma.c

   347	
   348	/**
   349	 * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel
   350	 * @dev:	struct device to get DMA request from
   351	 * @index:	index of FixedDMA descriptor for @dev
   352	 *
   353	 * Return:
   354	 * Pointer to appropriate dma channel on success or an error pointer.
   355	 */
   356	struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
   357			size_t index)
   358	{
   359		struct acpi_dma_parser_data pdata;
   360		struct acpi_dma_spec *dma_spec = &pdata.dma_spec;
   361		struct acpi_device *adev = ACPI_COMPANION(dev);
   362		struct list_head resource_list;
   363		struct acpi_dma *adma;
   364		struct dma_chan *chan = NULL;
   365		int found;
   366		int ret;
   367	
   368		memset(&pdata, 0, sizeof(pdata));
   369		pdata.index = index;
   370	
   371		/* Initial values for the request line and channel */
   372		dma_spec->chan_id = -1;
   373		dma_spec->slave_id = -1;
   374	
   375		INIT_LIST_HEAD(&resource_list);
   376		ret = acpi_dev_get_resources(adev, &resource_list,
   377					     acpi_dma_parse_fixed_dma, &pdata);
   378		acpi_dev_free_resource_list(&resource_list);
   379		if (ret < 0)
 > 380			return ret;
   381	
   382		if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0)
   383			return ERR_PTR(-ENODEV);
   384	
   385		mutex_lock(&acpi_dma_lock);
   386	
   387		list_for_each_entry(adma, &acpi_dma_list, dma_controllers) {
   388			/*
   389			 * We are not going to call translation function if slave_id
   390			 * doesn't fall to the request range.
   391			 */
   392			found = acpi_dma_update_dma_spec(adma, dma_spec);
   393			if (found < 0)
   394				continue;
   395			chan = adma->acpi_dma_xlate(dma_spec, adma);
   396			/*
   397			 * Try to get a channel only from the DMA controller that
   398			 * matches the slave_id. See acpi_dma_update_dma_spec()
   399			 * description for the details.
   400			 */
   401			if (found > 0 || chan)
   402				break;
   403		}
   404	
   405		mutex_unlock(&acpi_dma_lock);
   406		return chan ? chan : ERR_PTR(-EPROBE_DEFER);
   407	}
   408	EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index);
   409	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
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