Re: [Qemu-devel] [PATCH v6 01/13] m25p80: Add support for continuous read out of RDSR and READ_FSR

[mar.krzeminski]

Hi Francisco,

W dniu 01.11.2017 o 08:16, Francisco Iglesias pisze:
> Add support for continuous read out of the RDSR and READ_FSR status
> registers until the chip select is deasserted. This feature is supported
> by amongst others 1 or more flashtypes manufactured by Numonyx (Micron),
> Windbond, SST, Gigadevice, Eon and Macronix.
>
> Signed-off-by: Francisco Iglesias <address@hidden>
> ---
>   hw/block/m25p80.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c
> index a2438b9..721ae1a 100644
> --- a/hw/block/m25p80.c
> +++ b/hw/block/m25p80.c
> @@ -423,6 +423,7 @@ typedef struct Flash {
>       uint8_t data[M25P80_INTERNAL_DATA_BUFFER_SZ];
>       uint32_t len;
>       uint32_t pos;
> +    bool data_read_loop;
>       uint8_t needed_bytes;
>       uint8_t cmd_in_progress;
>       uint32_t cur_addr;
> @@ -983,6 +984,7 @@ static void decode_new_cmd(Flash *s, uint32_t value)
>           }
>           s->pos = 0;
>           s->len = 1;
> +        s->data_read_loop = true;
>           s->state = STATE_READING_DATA;
>           break;
>   
> @@ -993,6 +995,7 @@ static void decode_new_cmd(Flash *s, uint32_t value)
>           }
>           s->pos = 0;
>           s->len = 1;
> +        s->data_read_loop = true;
>           s->state = STATE_READING_DATA;
>           break;
>   
> @@ -1133,6 +1136,7 @@ static int m25p80_cs(SSISlave *ss, bool select)
>           s->pos = 0;
>           s->state = STATE_IDLE;
>           flash_sync_dirty(s, -1);
> +        s->data_read_loop = false;
>       }
>   
>       DB_PRINT_L(0, "%sselect\n", select ? "de" : "");
> @@ -1198,7 +1202,9 @@ static uint32_t m25p80_transfer8(SSISlave *ss, uint32_t 
> tx)
>           s->pos++;
>           if (s->pos == s->len) {
>               s->pos = 0;
> -            s->state = STATE_IDLE;
> +            if (!s->data_read_loop) {
> +                s->state = STATE_IDLE;
> +            }
>           }
>           break;
>   
> @@ -1279,6 +1285,7 @@ static const VMStateDescription vmstate_m25p80 = {
>           VMSTATE_UINT8_ARRAY(data, Flash, M25P80_INTERNAL_DATA_BUFFER_SZ),
>           VMSTATE_UINT32(len, Flash),
>           VMSTATE_UINT32(pos, Flash),
> +        VMSTATE_BOOL(data_read_loop, Flash),
This is not so simple I am afraid. Sorry I have not mentioned that in 
previous review.
Beside adding the field, you need to take care of VMSTATE (migration).
Documentation is here:
https://github.com/qemu/qemu/blob/master/docs/devel/migration.txt

My suggestion would be to bump version and just set false to 
data_read_loopwhen importing
older states - in fact it should be false by default, so do nothing?
Since I am away from Qemu for a while, and there are some new features 
(subsections),
could be that different solution is preferred.
Maybe Peter can help.

Regards,
Marcin
>           VMSTATE_UINT8(needed_bytes, Flash),
>           VMSTATE_UINT8(cmd_in_progress, Flash),
>           VMSTATE_UINT32(cur_addr, Flash),