Re: [PATCH 1/1] scsi-bus: Remove unused parameter state from scsi_dma_restart_cb

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

Hi Ray,

On 17/5/24 09:14, Ray Lee wrote:
> Signed-off-by: Ray Lee <hburaylee@gmail.com>
> ---
>   hw/scsi/scsi-bus.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
> index 9e40b0c920..7c3df9b31a 100644
> --- a/hw/scsi/scsi-bus.c
> +++ b/hw/scsi/scsi-bus.c
> @@ -255,7 +255,7 @@ static void scsi_dma_restart_req(SCSIRequest *req, void *opaque)
>       scsi_req_unref(req);
>   }
>   
> -static void scsi_dma_restart_cb(void *opaque, bool running, RunState state)
> +static void scsi_dma_restart_cb(void *opaque, bool running)
>   {
>       SCSIDevice *s = opaque;
>   

scsi_dma_restart_cb() is registered as callback:

  dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev),
                                                   scsi_dma_restart_cb,
                                                   dev);

The function prototype is (see include/sysemu/runstate.h):

   VMChangeStateEntry *
   qdev_add_vm_change_state_handler(DeviceState *dev,
                                    VMChangeStateHandler *cb,
                                    void *opaque);

and VMChangeStateHandler is defined as:

   typedef void VMChangeStateHandler(void *opaque,
                                     bool running,
                                     RunState state);

So even if the callback argument is not used, its prototype must
respect the VMChangeStateHandler definition. Thus your patch is
not correct. Indeed when building QEMU with your patch I get:

[152/339] Compiling C object libcommon.fa.p/hw_scsi_scsi-bus.c.o
../../hw/scsi/scsi-bus.c:359:13: error: incompatible function pointer 
types passing 'void (void *, bool)' to parameter of type 
'VMChangeStateHandler *' (aka 'void (*)(void *, bool, enum RunState)') 
[-Wincompatible-function-pointer-types]
             scsi_dma_restart_cb, dev);
             ^~~~~~~~~~~~~~~~~~~
include/sysemu/runstate.h:24:76: note: passing argument to parameter 
'cb' here
 
VMChangeStateHandler *cb,
 
    ^
1 error generated.

Please test your patch :)

Regards,

Phil.