[PATCH v10 0/1] genirq/devres: Add error handling in devm_request_threaded_irq() and devm_request_any_context_irq()

Pan Chuang posted 1 patch 2 months ago
kernel/irq/devres.c | 123 ++++++++++++++++++++++++++++++--------------
1 file changed, 83 insertions(+), 40 deletions(-)
[PATCH v10 0/1] genirq/devres: Add error handling in devm_request_threaded_irq() and devm_request_any_context_irq()
Posted by Pan Chuang 2 months ago
There are over 700 calls to devm_request_threaded_irq() and more than 1000
calls to devm_request_irq() in the kernel. Currently, most drivers implement
repetitive and inconsistent error handling for these functions:

1. Over 2000 lines of code are dedicated to error messages
2. Analysis shows 519 unique error messages with 323 variants after normalization
3. 186 messages provide no useful debugging information
4. Only a small fraction deliver meaningful error context

As tglx pointed out:
  "It's not a general allocator like kmalloc(). It's specialized and in the
   vast majority of cases failing to request the interrupt causes the device
   probe to fail. So having proper and consistent information why the device
   cannot be used is useful."

This patch implements a standardized error reporting approach[1]:

1. Renames existing functions to __devm_request_threaded_irq() and
   __devm_request_any_context_irq()

2. Adds devm_request_result() helper to unify error reporting:  
   a) Provides consistent diagnostic logging via dev_err_probe() on failure  
   b) Returns early with success code if no error occurred
 
3. Creates new devm_request_threaded_irq() and devm_request_any_context_irq()
   that:
   a) Invoke the underscore-prefixed variants
   b) Invokes devm_request_result() for centralized logging

The new error format provides complete debugging context:
  "<device>: error -<errcode>: request_irq(<irq>) <handler> <thread_fn> <devname>"

Example from our QEMU testing:
  test_irq_device: error -EINVAL: request_irq(1001) test_handler [test_irq] test_thread_fn [test_irq] irq-1001-failure

Based on the v9, add devm_request_result() helper.
https://lore.kernel.org/all/20250730062554.269151-2-panchuang@vivo.com/

[1]https://lore.kernel.org/all/87qzy9tvso.ffs@tglx/

Pan Chuang (1):
  genirq/devres: Add err handling in devm_request_threaded_irq() and
    devm_request_any_context_irq()

 kernel/irq/devres.c | 123 ++++++++++++++++++++++++++++++--------------
 1 file changed, 83 insertions(+), 40 deletions(-)

-- 
2.34.1