Re: [Qemu-devel] [PATCH v4 02/11] block: m25p80: RESET_ENABLE and RESET_MEMORY commnads

[Peter Crosthwaite]

"commands" in commit msg

On Mon, Feb 22, 2016 at 12:03 AM,  <address@hidden> wrote:
> From: Marcin Krzeminski <address@hidden>
>
> Signed-off-by: Marcin Krzeminski <address@hidden>
> ---
>  hw/block/m25p80.c | 35 ++++++++++++++++++++++++++++++++++-
>  1 file changed, 34 insertions(+), 1 deletion(-)
>
> diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c
> index 2222124..06b0af3 100644
> --- a/hw/block/m25p80.c
> +++ b/hw/block/m25p80.c
> @@ -233,6 +233,9 @@ typedef enum {
>      ERASE_4K = 0x20,
>      ERASE_32K = 0x52,
>      ERASE_SECTOR = 0xd8,
> +
> +    RESET_ENABLE = 0x66,
> +    RESET_MEMORY = 0x99,
>  } FlashCMD;
>
>  typedef enum {
> @@ -260,6 +263,7 @@ typedef struct Flash {
>      uint8_t cmd_in_progress;
>      uint64_t cur_addr;
>      bool write_enable;
> +    bool reset_enable;
>
>      int64_t dirty_page;
>
> @@ -432,11 +436,29 @@ static void complete_collecting_data(Flash *s)
>      }
>  }
>
> +static void reset_memory(Flash *s)
> +{
> +    s->cmd_in_progress = NOP;
> +    s->cur_addr = 0;
> +    s->len = 0;
> +    s->needed_bytes = 0;
> +    s->pos = 0;
> +    s->state = STATE_IDLE;
> +    s->write_enable = false;
> +    s->reset_enable = false;
> +
> +    DB_PRINT_L(0, "Reset done.\n");
> +}
> +
>  static void decode_new_cmd(Flash *s, uint32_t value)
>  {
>      s->cmd_in_progress = value;
>      DB_PRINT_L(0, "decoded new command:%x\n", value);
>
> +    if (value != RESET_MEMORY) {
> +        s->reset_enable = false;
> +    }
> +
>      switch (value) {
>
>      case ERASE_4K:
> @@ -541,6 +563,14 @@ static void decode_new_cmd(Flash *s, uint32_t value)
>          break;
>      case NOP:
>          break;
> +    case RESET_ENABLE:
> +        s->reset_enable = true;
> +        break;
> +    case RESET_MEMORY:
> +        if (s->reset_enable) {
> +            reset_memory(s);
> +        }
> +        break;
>      default:
>          qemu_log_mask(LOG_GUEST_ERROR, "M25P80: Unknown cmd %x\n", value);
>          break;
> @@ -622,6 +652,8 @@ static int m25p80_init(SSISlave *ss)
>      s->size = s->pi->sector_size * s->pi->n_sectors;
>      s->dirty_page = -1;
>
> +    reset_memory(s);
> +

This shouldn't be here, you need to add a Device::reset function. Your
use case of persisting data through a warn system reset (that we
discussed previously) is difficult to support with QEMUs current reset
semantics and your board is out-of-tree. So I think this should be in
the Device::reset and we need to revisit your unique use case along
with the addition of your board.

So with the move to device::reset,

Reviewed-by: Peter Crosthwaite <address@hidden>

>      /* FIXME use a qdev drive property instead of drive_get_next() */
>      dinfo = drive_get_next(IF_MTD);
>
> @@ -654,7 +686,7 @@ static void m25p80_pre_save(void *opaque)
>
>  static const VMStateDescription vmstate_m25p80 = {
>      .name = "xilinx_spi",
> -    .version_id = 1,
> +    .version_id = 2,
>      .minimum_version_id = 1,
>      .pre_save = m25p80_pre_save,
>      .fields = (VMStateField[]) {
> @@ -666,6 +698,7 @@ static const VMStateDescription vmstate_m25p80 = {
>          VMSTATE_UINT8(cmd_in_progress, Flash),
>          VMSTATE_UINT64(cur_addr, Flash),
>          VMSTATE_BOOL(write_enable, Flash),
> +        VMSTATE_BOOL(reset_enable, Flash),
>          VMSTATE_END_OF_LIST()
>      }
>  };
> --
> 2.5.0
>