2020-11-24 19:50:15

by Min Guo

Subject: [PATCH v2] usb: musb: remove unused variable 'devctl'

From: Min Guo <[email protected]>

Remove unused 'devctl' variable to fix compile warnings:

drivers/usb/musb/musbhsdma.c: In function 'dma_controller_irq':
drivers/usb/musb/musbhsdma.c:324:8: warning: variable 'devctl' set
but not used [-Wunused-but-set-variable]

Signed-off-by: Min Guo <[email protected]>
---
changes in v2
suggested by Alan Stern:
Add void before musb_read to indicate that the register MUSB_DEVCTL
was intended to be read and discarded.
---
drivers/usb/musb/musbhsdma.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/usb/musb/musbhsdma.c b/drivers/usb/musb/musbhsdma.c
index 0aacfc8be5a1..f59a009c533e 100644
--- a/drivers/usb/musb/musbhsdma.c
+++ b/drivers/usb/musb/musbhsdma.c
@@ -321,8 +321,6 @@ irqreturn_t dma_controller_irq(int irq, void *private_data)
musb_channel->channel.status =
MUSB_DMA_STATUS_BUS_ABORT;
} else {
- u8 devctl;
-
addr = musb_read_hsdma_addr(mbase,
bchannel);
channel->actual_len = addr
@@ -336,7 +334,7 @@ irqreturn_t dma_controller_irq(int irq, void *private_data)
< musb_channel->len) ?
"=> reconfig 0" : "=> complete");

- devctl = musb_readb(mbase, MUSB_DEVCTL);
+ (void)musb_readb(mbase, MUSB_DEVCTL);

channel->status = MUSB_DMA_STATUS_FREE;

--
2.18.0

2020-11-24 19:51:24

by Greg Kroah-Hartman

Subject: Re: [PATCH v2] usb: musb: remove unused variable 'devctl'

On Tue, Nov 24, 2020 at 02:36:13PM +0800, [email protected] wrote:
> From: Min Guo <[email protected]>
>
> Remove unused 'devctl' variable to fix compile warnings:
>
> drivers/usb/musb/musbhsdma.c: In function 'dma_controller_irq':
> drivers/usb/musb/musbhsdma.c:324:8: warning: variable 'devctl' set
> but not used [-Wunused-but-set-variable]
>
> Signed-off-by: Min Guo <[email protected]>
> ---
> changes in v2
> suggested by Alan Stern:
> Add void before musb_read to indicate that the register MUSB_DEVCTL
> was intended to be read and discarded.
> ---
> drivers/usb/musb/musbhsdma.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/usb/musb/musbhsdma.c b/drivers/usb/musb/musbhsdma.c
> index 0aacfc8be5a1..f59a009c533e 100644
> --- a/drivers/usb/musb/musbhsdma.c
> +++ b/drivers/usb/musb/musbhsdma.c
> @@ -321,8 +321,6 @@ irqreturn_t dma_controller_irq(int irq, void *private_data)
> musb_channel->channel.status =
> MUSB_DMA_STATUS_BUS_ABORT;
> } else {
> - u8 devctl;
> -
> addr = musb_read_hsdma_addr(mbase,
> bchannel);
> channel->actual_len = addr
> @@ -336,7 +334,7 @@ irqreturn_t dma_controller_irq(int irq, void *private_data)
> < musb_channel->len) ?
> "=> reconfig 0" : "=> complete");
>
> - devctl = musb_readb(mbase, MUSB_DEVCTL);
> + (void)musb_readb(mbase, MUSB_DEVCTL);

Please put a comment here as to why the read is happening so that people
do not throw it away sometime in the future.

thanks,

greg k-h