[PATCH] PCI/MSI: Simplify the return value of arch_setup_msi_irqs

[PATCH] PCI/MSI: Simplify the return value of arch_setup_msi_irqs

[Shawn Lin]

No any callers do care whether arch_setup_msi_irqs returns
-ENOSPC or other error numbers. That means they treat the
negative numbers in the same way. So there shouldn't make any
difference to directly return -ENOSPC if finding it's non-zero.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
---

 drivers/pci/msi.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index a080f44..4a40b72 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -108,7 +108,7 @@ int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 {
 	struct msi_controller *chip = dev->bus->msi;
 	struct msi_desc *entry;
-	int ret;
+	int ret = 0;
 
 	if (chip && chip->setup_irqs)
 		return chip->setup_irqs(chip, dev, nvec, type);
@@ -119,13 +119,10 @@ int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 	if (type == PCI_CAP_ID_MSI && nvec > 1)
 		return 1;
 
-	for_each_pci_msi_entry(entry, dev) {
+	for_each_pci_msi_entry(entry, dev)
 		ret = arch_setup_msi_irq(dev, entry);
-		if (ret < 0)
-			return ret;
-		if (ret > 0)
+		if (ret)
 			return -ENOSPC;
-	}
 
 	return 0;
 }
-- 
2.3.7

Re: [PATCH] PCI/MSI: Simplify the return value of arch_setup_msi_irqs

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 2699 bytes --]

Hi,

[auto build test WARNING on pci/next]
[also build test WARNING on v4.7-rc4 next-20160621]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Shawn-Lin/PCI-MSI-Simplify-the-return-value-of-arch_setup_msi_irqs/20160622-103824
base:   https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
config: i386-defconfig (attached as .config)
compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All warnings (new ones prefixed by >>):

   In file included from include/linux/preempt.h:10:0,
                    from include/linux/spinlock.h:50,
                    from include/linux/mmzone.h:7,
                    from include/linux/gfp.h:5,
                    from include/linux/mm.h:9,
                    from drivers/pci/msi.c:10:
   drivers/pci/msi.c: In function 'arch_setup_msi_irqs':
   include/linux/list.h:447:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
     for (pos = list_first_entry(head, typeof(*pos), member); \
     ^
>> include/linux/msi.h:108:2: note: in expansion of macro 'list_for_each_entry'
     list_for_each_entry((desc), dev_to_msi_list((dev)), list)
     ^~~~~~~~~~~~~~~~~~~
>> include/linux/msi.h:113:2: note: in expansion of macro 'for_each_msi_entry'
     for_each_msi_entry((desc), &(pdev)->dev)
     ^~~~~~~~~~~~~~~~~~
>> drivers/pci/msi.c:122:2: note: in expansion of macro 'for_each_pci_msi_entry'
     for_each_pci_msi_entry(entry, dev)
     ^~~~~~~~~~~~~~~~~~~~~~
   drivers/pci/msi.c:124:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
      if (ret)
      ^~

vim +/for_each_pci_msi_entry +122 drivers/pci/msi.c

   106	
   107	int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
   108	{
   109		struct msi_controller *chip = dev->bus->msi;
   110		struct msi_desc *entry;
   111		int ret = 0;
   112	
   113		if (chip && chip->setup_irqs)
   114			return chip->setup_irqs(chip, dev, nvec, type);
   115		/*
   116		 * If an architecture wants to support multiple MSI, it needs to
   117		 * override arch_setup_msi_irqs()
   118		 */
   119		if (type == PCI_CAP_ID_MSI && nvec > 1)
   120			return 1;
   121	
 > 122		for_each_pci_msi_entry(entry, dev)
   123			ret = arch_setup_msi_irq(dev, entry);
   124			if (ret)
   125				return -ENOSPC;
   126	
   127		return 0;
   128	}
   129	
   130	/*

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/octet-stream, Size: 24880 bytes --]