| Message ID | 20190508164934.GA20064@embeddedor (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Darren Hart |
| Headers | show |
| Series | platform/x86: acer-wmi: Mark expected switch fall-throughs | expand |
On Wed, May 08, 2019 at 11:49:34AM -0500, Gustavo A. R. Silva wrote: > In preparation to enabling -Wimplicit-fallthrough, mark switch > cases where we are expecting to fall through. > > This patch fixes the following warnings: > > drivers/platform/x86/acer-wmi.c: In function ‘set_u32’: > drivers/platform/x86/acer-wmi.c:1378:33: warning: this statement may fall through [-Wimplicit-fallthrough=] > if (cap == ACER_CAP_WIRELESS || > ^ > drivers/platform/x86/acer-wmi.c:1386:3: note: here > case ACER_WMID: > ^~~~ > drivers/platform/x86/acer-wmi.c:1393:12: warning: this statement may fall through [-Wimplicit-fallthrough=] > else if (wmi_has_guid(WMID_GUID2)) > ^ > drivers/platform/x86/acer-wmi.c:1395:3: note: here > default: > ^~~~~~~ > drivers/platform/x86/acer-wmi.c: In function ‘get_u32’: > drivers/platform/x86/acer-wmi.c:1340:6: warning: this statement may fall through [-Wimplicit-fallthrough=] > if (cap == ACER_CAP_MAILLED) { > ^ > drivers/platform/x86/acer-wmi.c:1344:2: note: here > case ACER_WMID: > ^~~~ > drivers/platform/x86/acer-wmi.c: In function ‘WMID_get_u32’: > drivers/platform/x86/acer-wmi.c:1013:6: warning: this statement may fall through [-Wimplicit-fallthrough=] > if (quirks->mailled == 1) { > ^ > drivers/platform/x86/acer-wmi.c:1018:2: note: here > default: > ^~~~~~~ > > Warning level 3 was used: -Wimplicit-fallthrough=3 > > This patch is part of the ongoing efforts to enable > -Wimplicit-fallthrough. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > --- > drivers/platform/x86/acer-wmi.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c > index fcfeadd1301f..bd87f9037f95 100644 > --- a/drivers/platform/x86/acer-wmi.c > +++ b/drivers/platform/x86/acer-wmi.c > @@ -1015,6 +1015,7 @@ static acpi_status WMID_get_u32(u32 *value, u32 cap) > *value = tmp & 0x1; > return 0; > } > + /* fall through */ > default: > return AE_ERROR; > } > @@ -1341,6 +1342,7 @@ static acpi_status get_u32(u32 *value, u32 cap) > status = AMW0_get_u32(value, cap); > break; > } > + /* fall through */ This doesn't strike me as obviously the right thing to do here. If the interface type is AMW0_V2, why is it the right thing to do to use WMID_get_u32 if the cap isn't ACER_CAP_MAILLED? > case ACER_WMID: > status = WMID_get_u32(value, cap); > break; > @@ -1383,6 +1385,7 @@ static acpi_status set_u32(u32 value, u32 cap) > > return AMW0_set_u32(value, cap); > } > + /* fall through */ Similarly here. Are we documenting intended behavior, or covering up a bug. > case ACER_WMID: > return WMID_set_u32(value, cap);
Darren, Please, see my comments below... On 5/8/19 6:06 PM, Darren Hart wrote: > On Wed, May 08, 2019 at 11:49:34AM -0500, Gustavo A. R. Silva wrote: >> In preparation to enabling -Wimplicit-fallthrough, mark switch >> cases where we are expecting to fall through. >> >> This patch fixes the following warnings: >> >> drivers/platform/x86/acer-wmi.c: In function ‘set_u32’: >> drivers/platform/x86/acer-wmi.c:1378:33: warning: this statement may fall through [-Wimplicit-fallthrough=] >> if (cap == ACER_CAP_WIRELESS || >> ^ >> drivers/platform/x86/acer-wmi.c:1386:3: note: here >> case ACER_WMID: >> ^~~~ >> drivers/platform/x86/acer-wmi.c:1393:12: warning: this statement may fall through [-Wimplicit-fallthrough=] >> else if (wmi_has_guid(WMID_GUID2)) >> ^ >> drivers/platform/x86/acer-wmi.c:1395:3: note: here >> default: >> ^~~~~~~ >> drivers/platform/x86/acer-wmi.c: In function ‘get_u32’: >> drivers/platform/x86/acer-wmi.c:1340:6: warning: this statement may fall through [-Wimplicit-fallthrough=] >> if (cap == ACER_CAP_MAILLED) { >> ^ >> drivers/platform/x86/acer-wmi.c:1344:2: note: here >> case ACER_WMID: >> ^~~~ >> drivers/platform/x86/acer-wmi.c: In function ‘WMID_get_u32’: >> drivers/platform/x86/acer-wmi.c:1013:6: warning: this statement may fall through [-Wimplicit-fallthrough=] >> if (quirks->mailled == 1) { >> ^ >> drivers/platform/x86/acer-wmi.c:1018:2: note: here >> default: >> ^~~~~~~ >> >> Warning level 3 was used: -Wimplicit-fallthrough=3 >> >> This patch is part of the ongoing efforts to enable >> -Wimplicit-fallthrough. >> >> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> >> --- >> drivers/platform/x86/acer-wmi.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c >> index fcfeadd1301f..bd87f9037f95 100644 >> --- a/drivers/platform/x86/acer-wmi.c >> +++ b/drivers/platform/x86/acer-wmi.c >> @@ -1015,6 +1015,7 @@ static acpi_status WMID_get_u32(u32 *value, u32 cap) >> *value = tmp & 0x1; >> return 0; >> } >> + /* fall through */ >> default: >> return AE_ERROR; >> } >> @@ -1341,6 +1342,7 @@ static acpi_status get_u32(u32 *value, u32 cap) >> status = AMW0_get_u32(value, cap); >> break; >> } >> + /* fall through */ > > This doesn't strike me as obviously the right thing to do here. If the interface > type is AMW0_V2, why is it the right thing to do to use WMID_get_u32 if the cap > isn't ACER_CAP_MAILLED? > In commit commit 745a5d2126926808295742932d0e36d485efa485 case ACER_AMW0_V2 falls through to case ACER_WMID deliberately in function set_u32(), without reporting any error or warning. So, I thought it was fair to assume that the fall-through is intentional in both functions get_u32() and set_u32(). Otherwise I would expect to see a message indicating that interface ACER_AMW0_V2 is unavailable in function set_u32(). This is also complemented by the following... >> case ACER_WMID: >> status = WMID_get_u32(value, cap); >> break; >> @@ -1383,6 +1385,7 @@ static acpi_status set_u32(u32 value, u32 cap) >> >> return AMW0_set_u32(value, cap); >> } >> + /* fall through */ > > Similarly here. > > Are we documenting intended behavior, or covering up a bug. > Commit 5c742b45dd5fbbb6cf74d3378341704f4b23c5e8 mentions that "This was fixed in acer_acpi some time ago, but I forgot to port the patch over to acer-wmi when it was merged." Notice that this driver (acer-wmi) is based on the no-longer existing acer_acpi driver. But after googling for a while I could found the fix the original author talks about: https://repo.or.cz/acer_acpi.git/commitdiff/74c08a38875ffa9989c3100947650ac8a388c189 So, the fix is indeed similar and contains the same fall-throughs from case ACER_AMW0_V2 to case ACER_WMID in both functions get_u32() and set_u32(). Thanks -- Gustavo
On Thu, May 9, 2019 at 4:48 AM Gustavo A. R. Silva <gustavo@embeddedor.com> wrote: > Commit 5c742b45dd5fbbb6cf74d3378341704f4b23c5e8 mentions that "This was fixed > in acer_acpi some time ago, but I forgot to port the patch over to acer-wmi > when it was merged." Notice that this driver (acer-wmi) is based on the > no-longer existing acer_acpi driver. But after googling for a while I could > found the fix the original author talks about: > > https://repo.or.cz/acer_acpi.git/commitdiff/74c08a38875ffa9989c3100947650ac8a388c189 > > So, the fix is indeed similar and contains the same fall-throughs from case > ACER_AMW0_V2 to case ACER_WMID in both functions get_u32() and set_u32(). Pushed to my review and testing queue, thanks!
diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c index fcfeadd1301f..bd87f9037f95 100644 --- a/drivers/platform/x86/acer-wmi.c +++ b/drivers/platform/x86/acer-wmi.c @@ -1015,6 +1015,7 @@ static acpi_status WMID_get_u32(u32 *value, u32 cap) *value = tmp & 0x1; return 0; } + /* fall through */ default: return AE_ERROR; } @@ -1341,6 +1342,7 @@ static acpi_status get_u32(u32 *value, u32 cap) status = AMW0_get_u32(value, cap); break; } + /* fall through */ case ACER_WMID: status = WMID_get_u32(value, cap); break; @@ -1383,6 +1385,7 @@ static acpi_status set_u32(u32 value, u32 cap) return AMW0_set_u32(value, cap); } + /* fall through */ case ACER_WMID: return WMID_set_u32(value, cap); case ACER_WMID_v2: @@ -1392,6 +1395,7 @@ static acpi_status set_u32(u32 value, u32 cap) return wmid_v2_set_u32(value, cap); else if (wmi_has_guid(WMID_GUID2)) return WMID_set_u32(value, cap); + /* fall through */ default: return AE_BAD_PARAMETER; }
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. This patch fixes the following warnings: drivers/platform/x86/acer-wmi.c: In function ‘set_u32’: drivers/platform/x86/acer-wmi.c:1378:33: warning: this statement may fall through [-Wimplicit-fallthrough=] if (cap == ACER_CAP_WIRELESS || ^ drivers/platform/x86/acer-wmi.c:1386:3: note: here case ACER_WMID: ^~~~ drivers/platform/x86/acer-wmi.c:1393:12: warning: this statement may fall through [-Wimplicit-fallthrough=] else if (wmi_has_guid(WMID_GUID2)) ^ drivers/platform/x86/acer-wmi.c:1395:3: note: here default: ^~~~~~~ drivers/platform/x86/acer-wmi.c: In function ‘get_u32’: drivers/platform/x86/acer-wmi.c:1340:6: warning: this statement may fall through [-Wimplicit-fallthrough=] if (cap == ACER_CAP_MAILLED) { ^ drivers/platform/x86/acer-wmi.c:1344:2: note: here case ACER_WMID: ^~~~ drivers/platform/x86/acer-wmi.c: In function ‘WMID_get_u32’: drivers/platform/x86/acer-wmi.c:1013:6: warning: this statement may fall through [-Wimplicit-fallthrough=] if (quirks->mailled == 1) { ^ drivers/platform/x86/acer-wmi.c:1018:2: note: here default: ^~~~~~~ Warning level 3 was used: -Wimplicit-fallthrough=3 This patch is part of the ongoing efforts to enable -Wimplicit-fallthrough. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/platform/x86/acer-wmi.c | 4 ++++ 1 file changed, 4 insertions(+)