Re: [Qemu-devel] [PATCH 12/23] ide: Convert FLUSH CACHE to ide_cmd_table handler

[Alex Williamson <alex.williamson@redhat.com>]

On Mon, 2013-06-24 at 11:10 +0200, Stefan Hajnoczi wrote:
> From: Kevin Wolf <kwolf@redhat.com>
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  hw/ide/core.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/ide/core.c b/hw/ide/core.c
> index 8789758..83e86aa 100644
> --- a/hw/ide/core.c
> +++ b/hw/ide/core.c
> @@ -1184,6 +1184,12 @@ static bool cmd_write_dma(IDEState *s, uint8_t cmd)
>      return false;
>  }
>  
> +static bool cmd_flush_cache(IDEState *s, uint8_t cmd)
> +{
> +    ide_flush_cache(s);
> +    return false;
> +}
> +
>  static bool cmd_read_native_max(IDEState *s, uint8_t cmd)
>  {
>      bool lba48 = (cmd == WIN_READ_NATIVE_MAX_EXT);
> @@ -1345,8 +1351,8 @@ static const struct {
>      [WIN_SETIDLE1]                = { cmd_nop, ALL_OK },
>      [WIN_CHECKPOWERMODE1]         = { cmd_check_power_mode, ALL_OK | SET_DSC },
>      [WIN_SLEEPNOW1]               = { cmd_nop, ALL_OK },
> -    [WIN_FLUSH_CACHE]             = { NULL, ALL_OK },
> -    [WIN_FLUSH_CACHE_EXT]         = { NULL, HD_CFA_OK },
> +    [WIN_FLUSH_CACHE]             = { cmd_flush_cache, ALL_OK },
> +    [WIN_FLUSH_CACHE_EXT]         = { cmd_flush_cache, HD_CFA_OK },
>      [WIN_IDENTIFY]                = { cmd_identify, ALL_OK },
>      [WIN_SETFEATURES]             = { cmd_set_features, ALL_OK | SET_DSC },
>      [IBM_SENSE_CONDITION]         = { NULL, CFA_OK },
> @@ -1403,10 +1409,6 @@ void ide_exec_cmd(IDEBus *bus, uint32_t val)
>      }
>  
>      switch(val) {
> -    case WIN_FLUSH_CACHE:
> -    case WIN_FLUSH_CACHE_EXT:
> -        ide_flush_cache(s);
> -        break;
>      case WIN_SEEK:
>          /* XXX: Check that seek is within bounds */
>          s->status = READY_STAT | SEEK_STAT;

This also breaks win7 x64 q35 IDE.  Note that while this change looks
like a no-op, filling in a handler now means that we do:

s->status = READY_STAT | BUSY_STAT;

before calling the handler and don't clear it on the way out since the
function statically returns false.  This then introduces the same bug as
f68ec837.  Thanks,

Alex