On Fri, Mar 22, 2019 at 4:00 PM Takashi Iwai tiwai@suse.de wrote:
On Fri, 22 Mar 2019 15:06:28 +0100, Arnd Bergmann wrote:
When CONFIG_PCI is disabled, clang gets confused about the control flow of the switch() statement always ending up in the default case, and warns:
sound/pci/hda/patch_ca0132.c:7558:6: error: variable 'fw_entry' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] if (!spec->alt_firmware_present) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~ sound/pci/hda/patch_ca0132.c:7565:42: note: uninitialized use occurs here dsp_os_image = (struct dsp_image_seg *)(fw_entry->data); ^~~~~~~~ sound/pci/hda/patch_ca0132.c:7558:2: note: remove the 'if' if its condition is always true if (!spec->alt_firmware_present) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ sound/pci/hda/patch_ca0132.c:7521:33: note: initialize the variable 'fw_entry' to silence this warning const struct firmware *fw_entry; ^ = NULL
Adding an explicit check for CONFIG_PCI avoids the issue. Unfortunately this is not very intuitive here.
Link: https://bugs.llvm.org/show_bug.cgi?id=41197#c1 Signed-off-by: Arnd Bergmann arnd@arndb.de
Any suggestions for other workarounds appreciated. If you can think of a better fix, please treat this as a reported-by:
Can it be addressed by the code simplification like below, instead?
Yes, I confirmed this works as well, and it's probably more obvious what's going on, so let's use your version.
Thanks,
Arnd