2023-07-31 12:46:17

by Gautam Menghani

[permalink] [raw]
Subject: [PATCH v2] arch/powerpc: Remove unnecessary endian conversion code in XICS

Remove an unnecessary piece of code that does an endianness conversion but
does not use the result. The following warning was reported by Clang's
static analyzer:

arch/powerpc/sysdev/xics/ics-opal.c:114:2: warning: Value stored to
'server' is never read [deadcode.DeadStores]
server = be16_to_cpu(oserver);

'server' was used as a parameter to opal_get_xive() in commit
5c7c1e9444d8 ("powerpc/powernv: Add OPAL ICS backend") when it was
introduced. 'server' was also used in an error message for the call to
opal_get_xive().

'server' was always later set by a call to ics_opal_mangle_server()
before being used.

Commit bf8e0f891a32 ("powerpc/powernv: Fix endian issues in OPAL ICS
backend") used a new variable 'oserver' as the parameter to
opal_get_xive() instead of 'server' for endian correctness. It also
removed 'server' from the error message for the call to opal_get_xive().

Fix the warning by removing the server variable assignment.

Fixes: bf8e0f891a32 ("powerpc/powernv: Fix endian issues in OPAL ICS backend")
Reviewed-by: Jordan Niethe <[email protected]>
Signed-off-by: Gautam Menghani <[email protected]>
---
V1 -> V2:
1. Add context of the code provided by Jordan
2. Add fixes tag

arch/powerpc/sysdev/xics/ics-opal.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/sysdev/xics/ics-opal.c b/arch/powerpc/sysdev/xics/ics-opal.c
index 6cfbb4fac7fb..5fe73dabab79 100644
--- a/arch/powerpc/sysdev/xics/ics-opal.c
+++ b/arch/powerpc/sysdev/xics/ics-opal.c
@@ -111,7 +111,6 @@ static int ics_opal_set_affinity(struct irq_data *d,
__func__, d->irq, hw_irq, rc);
return -1;
}
- server = be16_to_cpu(oserver);

wanted_server = xics_get_irq_server(d->irq, cpumask, 1);
if (wanted_server < 0) {
--
2.41.0



2023-08-23 14:44:12

by Michael Ellerman

[permalink] [raw]
Subject: Re: [PATCH v2] arch/powerpc: Remove unnecessary endian conversion code in XICS

On Mon, 31 Jul 2023 17:25:39 +0530, Gautam Menghani wrote:
> Remove an unnecessary piece of code that does an endianness conversion but
> does not use the result. The following warning was reported by Clang's
> static analyzer:
>
> arch/powerpc/sysdev/xics/ics-opal.c:114:2: warning: Value stored to
> 'server' is never read [deadcode.DeadStores]
> server = be16_to_cpu(oserver);
>
> [...]

Applied to powerpc/next.

[1/1] arch/powerpc: Remove unnecessary endian conversion code in XICS
https://git.kernel.org/powerpc/c/984b07b428994d9e83c6de9a5f1307948188fe71

cheers