Re: [PATCH v2 30/30] misc: cxl: flash: Remove unused pointer
On Wed, 01 Jul 2020, Greg KH wrote:
> On Wed, Jul 01, 2020 at 09:31:18AM +0100, Lee Jones wrote:
> > The DRC index pointer us updated on an OPCODE_ADD, but never
> > actually read. Remove the used pointer and shift up OPCODE_ADD
> > to group with OPCODE_DELETE which also provides a noop.
> >
> > Fixes the following W=1 kernel build warning:
> >
> > drivers/misc/cxl/flash.c: In function ‘update_devicetree’:
> > drivers/misc/cxl/flash.c:178:16: warning: variable ‘drc_index’ set but not
> > used [-Wunused-but-set-variable]
> > 178 | __be32 *data, drc_index, phandle;
> > | ^
> >
> > Cc: Frederic Barrat
> > Cc: Andrew Donnellan
> > Cc: linuxppc-dev@lists.ozlabs.org
> > Signed-off-by: Lee Jones
> > ---
> > drivers/misc/cxl/flash.c | 7 ++-
> > 1 file changed, 2 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/misc/cxl/flash.c b/drivers/misc/cxl/flash.c
> > index cb9cca35a2263..24e3dfcc91a74 100644
> > --- a/drivers/misc/cxl/flash.c
> > +++ b/drivers/misc/cxl/flash.c
> > @@ -175,7 +175,7 @@ static int update_devicetree(struct cxl *adapter, s32
> > scope)
> > struct update_nodes_workarea *unwa;
> > u32 action, node_count;
> > int token, rc, i;
> > - __be32 *data, drc_index, phandle;
> > + __be32 *data, phandle;
> > char *buf;
> >
> > token = rtas_token("ibm,update-nodes");
> > @@ -206,15 +206,12 @@ static int update_devicetree(struct cxl *adapter, s32
> > scope)
> >
> > switch (action) {
> > case OPCODE_DELETE:
> > + case OPCODE_ADD:
> > /* nothing to do */
> > break;
> > case OPCODE_UPDATE:
> > update_node(phandle, scope);
> > break;
> > - case OPCODE_ADD:
> > - /* nothing to do, just move pointer */
> > - drc_index = *data++;
> > - break;
>
> I think this is not correct, as *data++ changes the value there, and so
> this changes the logic of the code.
Great spot.
Looks like I overlooked that the pointer itself is being incremented.
> Dropping this one from my queue.
Sounds good.
I'll fix-up and send this separately at a later date.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
Re: [PATCH v2 30/30] misc: cxl: flash: Remove unused pointer
On Wed, Jul 01, 2020 at 09:31:18AM +0100, Lee Jones wrote:
> The DRC index pointer us updated on an OPCODE_ADD, but never
> actually read. Remove the used pointer and shift up OPCODE_ADD
> to group with OPCODE_DELETE which also provides a noop.
>
> Fixes the following W=1 kernel build warning:
>
> drivers/misc/cxl/flash.c: In function ‘update_devicetree’:
> drivers/misc/cxl/flash.c:178:16: warning: variable ‘drc_index’ set but not
> used [-Wunused-but-set-variable]
> 178 | __be32 *data, drc_index, phandle;
> | ^
>
> Cc: Frederic Barrat
> Cc: Andrew Donnellan
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Lee Jones
> ---
> drivers/misc/cxl/flash.c | 7 ++-
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/misc/cxl/flash.c b/drivers/misc/cxl/flash.c
> index cb9cca35a2263..24e3dfcc91a74 100644
> --- a/drivers/misc/cxl/flash.c
> +++ b/drivers/misc/cxl/flash.c
> @@ -175,7 +175,7 @@ static int update_devicetree(struct cxl *adapter, s32
> scope)
> struct update_nodes_workarea *unwa;
> u32 action, node_count;
> int token, rc, i;
> - __be32 *data, drc_index, phandle;
> + __be32 *data, phandle;
> char *buf;
>
> token = rtas_token("ibm,update-nodes");
> @@ -206,15 +206,12 @@ static int update_devicetree(struct cxl *adapter, s32
> scope)
>
> switch (action) {
> case OPCODE_DELETE:
> + case OPCODE_ADD:
> /* nothing to do */
> break;
> case OPCODE_UPDATE:
> update_node(phandle, scope);
> break;
> - case OPCODE_ADD:
> - /* nothing to do, just move pointer */
> - drc_index = *data++;
> - break;
I think this is not correct, as *data++ changes the value there, and so
this changes the logic of the code.
Dropping this one from my queue.
thanks,
greg k-h
[PATCH v2 30/30] misc: cxl: flash: Remove unused pointer
The DRC index pointer us updated on an OPCODE_ADD, but never
actually read. Remove the used pointer and shift up OPCODE_ADD
to group with OPCODE_DELETE which also provides a noop.
Fixes the following W=1 kernel build warning:
drivers/misc/cxl/flash.c: In function ‘update_devicetree’:
drivers/misc/cxl/flash.c:178:16: warning: variable ‘drc_index’ set but not
used [-Wunused-but-set-variable]
178 | __be32 *data, drc_index, phandle;
| ^
Cc: Frederic Barrat
Cc: Andrew Donnellan
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Lee Jones
---
drivers/misc/cxl/flash.c | 7 ++-
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/misc/cxl/flash.c b/drivers/misc/cxl/flash.c
index cb9cca35a2263..24e3dfcc91a74 100644
--- a/drivers/misc/cxl/flash.c
+++ b/drivers/misc/cxl/flash.c
@@ -175,7 +175,7 @@ static int update_devicetree(struct cxl *adapter, s32 scope)
struct update_nodes_workarea *unwa;
u32 action, node_count;
int token, rc, i;
- __be32 *data, drc_index, phandle;
+ __be32 *data, phandle;
char *buf;
token = rtas_token("ibm,update-nodes");
@@ -206,15 +206,12 @@ static int update_devicetree(struct cxl *adapter, s32
scope)
switch (action) {
case OPCODE_DELETE:
+ case OPCODE_ADD:
/* nothing to do */
break;
case OPCODE_UPDATE:
update_node(phandle, scope);
break;
- case OPCODE_ADD:
- /* nothing to do, just move pointer */
- drc_index = *data++;
- break;
}
}
}
--
2.25.1
