Re: [PATCH 7/8] drm/vmwgfx: Implement MSI/MSI-X support for IRQs

[kernel test robot <lkp@intel.com>]

Hi Zack,

I love your patch! Perhaps something to improve:

[auto build test WARNING on drm/drm-next]
[also build test WARNING on drm-intel/for-linux-next drm-tip/drm-tip drm-exynos/exynos-drm-next tegra-drm/drm/tegra/for-next v5.17-rc6 next-20220302]
[cannot apply to airlied/drm-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Zack-Rusin/drm-vmwgfx-3D-on-arm64-and-large-cursor-support/20220302-232641
base:   git://anongit.freedesktop.org/drm/drm drm-next
config: i386-randconfig-a004 (https://download.01.org/0day-ci/archive/20220303/202203030802.itIYtJH1-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project d271fc04d5b97b12e6b797c6067d3c96a8d7470e)
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
        # https://github.com/0day-ci/linux/commit/63d27e1cb11562966a6f07bf0e667b0a54dc2412
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Zack-Rusin/drm-vmwgfx-3D-on-arm64-and-large-cursor-support/20220302-232641
        git checkout 63d27e1cb11562966a6f07bf0e667b0a54dc2412
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/gpu/drm/vmwgfx/

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 >>):

>> drivers/gpu/drm/vmwgfx/vmwgfx_irq.c:340:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
           if (nvec <= 0) {
               ^~~~~~~~~
   drivers/gpu/drm/vmwgfx/vmwgfx_irq.c:369:9: note: uninitialized use occurs here
           return ret;
                  ^~~
   drivers/gpu/drm/vmwgfx/vmwgfx_irq.c:340:2: note: remove the 'if' if its condition is always false
           if (nvec <= 0) {
           ^~~~~~~~~~~~~~~~
   drivers/gpu/drm/vmwgfx/vmwgfx_irq.c:330:9: note: initialize the variable 'ret' to silence this warning
           int ret;
                  ^
                   = 0
   1 warning generated.


vim +340 drivers/gpu/drm/vmwgfx/vmwgfx_irq.c

   319	
   320	/**
   321	 * vmw_irq_install - Install the irq handlers
   322	 *
   323	 * @dev_priv:  Pointer to the vmw_private device.
   324	 * Return:  Zero if successful. Negative number otherwise.
   325	 */
   326	int vmw_irq_install(struct vmw_private *dev_priv)
   327	{
   328		struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
   329		struct drm_device *dev = &dev_priv->drm;
   330		int ret;
   331		int nvec;
   332		int i = 0;
   333	
   334		BUILD_BUG_ON((SVGA_IRQFLAG_MAX >> VMWGFX_MAX_NUM_IRQS) != 1);
   335		BUG_ON(VMWGFX_MAX_NUM_IRQS != get_count_order(SVGA_IRQFLAG_MAX));
   336	
   337		nvec = pci_alloc_irq_vectors(pdev, 1, VMWGFX_MAX_NUM_IRQS,
   338					     PCI_IRQ_ALL_TYPES);
   339	
 > 340		if (nvec <= 0) {

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