[PATCH v10] drm/i915: WA context support for L3flush

[Dan Carpenter]

Hi Nitin,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Nitin-Gote/drm-i915-WA-context-support-for-L3flush/20240814-231915
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
patch link:    https://lore.kernel.org/r/20240813061657.925443-1-nitin.r.gote%40intel.com
patch subject: [PATCH v10] drm/i915: WA context support for L3flush
config: i386-randconfig-141-20240816 (https://download.01.org/0day-ci/archive/20240817/202408170547.2jcHHUAr-lkp@intel.com/config)
compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp at intel.com>
| Reported-by: Dan Carpenter <dan.carpenter at linaro.org>
| Closes: https://lore.kernel.org/r/202408170547.2jcHHUAr-lkp@intel.com/

New smatch warnings:
drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c:4415 guc_kernel_context_pin() error: uninitialized symbol 'ret'.

vim +/ret +4415 drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4387  static inline int guc_kernel_context_pin(struct intel_guc *guc,
3a4cdf1982f05d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c Matthew Brost         2021-07-21  4388  					 struct intel_context *ce)
3a4cdf1982f05d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c Matthew Brost         2021-07-21  4389  {
cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4390  	int ret;
cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4391  
58ea7d620c5ebc drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2022-03-01  4392  	/*
58ea7d620c5ebc drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2022-03-01  4393  	 * Note: we purposefully do not check the returns below because
58ea7d620c5ebc drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2022-03-01  4394  	 * the registration can only fail if a reset is just starting.

Is this comment out of date?  Which returns aren't checked?

58ea7d620c5ebc drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2022-03-01  4395  	 * This is called at the end of reset so presumably another reset
58ea7d620c5ebc drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2022-03-01  4396  	 * isn't happening and even it did this code would be run again.
58ea7d620c5ebc drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2022-03-01  4397  	 */
58ea7d620c5ebc drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2022-03-01  4398  
cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4399  	if (context_guc_id_invalid(ce)) {
cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4400  		ret = pin_guc_id(guc, ce);
cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4401  
cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4402  		if (ret < 0)
cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4403  			return ret;
cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4404  	}
58ea7d620c5ebc drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2022-03-01  4405  
de51de9672a17e drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2022-11-02  4406  	if (!test_bit(CONTEXT_GUC_INIT, &ce->flags))
de51de9672a17e drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2022-11-02  4407  		guc_context_init(ce);
de51de9672a17e drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2022-11-02  4408  
078a89e7d6f60a drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c Venkata Ramana Nayana 2024-08-13  4409  	if (!intel_context_is_hidden(ce)) {
cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4410  		ret = try_context_registration(ce, true);
cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4411  		if (ret)
cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4412  			unpin_guc_id(guc, ce);
078a89e7d6f60a drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c Venkata Ramana Nayana 2024-08-13  4413  	}

ret is uninitialized of context_guc_id_invalid() is false and
intel_context_is_hidden() is true.

cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17  4414  
cd414f4f59f64d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c John Harrison         2023-02-17 @4415  	return ret;
3a4cdf1982f05d drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c Matthew Brost         2021-07-21  4416  }

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