Re: [PATCH 6/9] hw/ide/ahci: PxSACT and PxCI is cleared when PxCMD.ST is cleared

From: John Snow <jsnow@redhat.com>
To: Niklas Cassel <nks@flawful.org>
Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org,
	 Damien Le Moal <dlemoal@kernel.org>,
	Niklas Cassel <niklas.cassel@wdc.com>
Subject: Re: [PATCH 6/9] hw/ide/ahci: PxSACT and PxCI is cleared when PxCMD.ST is cleared
Date: Wed, 17 May 2023 17:21:39 -0400	[thread overview]
Message-ID: <CAFn=p-bHgKnFXfsTVoP9XotnNEV_oQ=tAqzh2SUDsYxeZBWXKg@mail.gmail.com> (raw)
In-Reply-To: <20230428132124.670840-7-nks@flawful.org>

On Fri, Apr 28, 2023 at 9:23 AM Niklas Cassel <nks@flawful.org> wrote:
>
> From: Niklas Cassel <niklas.cassel@wdc.com>
>
> According to AHCI 1.3.1 definition of PxSACT:
> This field is cleared when PxCMD.ST is written from a '1' to a '0' by
> software. This field is not cleared by a COMRESET or a software reset.
>
> According to AHCI 1.3.1 definition of PxCI:
> This field is also cleared when PxCMD.ST is written from a '1' to a '0'
> by software.
>
> Clearing PxCMD.ST is part of the error recovery procedure, see
> AHCI 1.3.1, section "6.2 Error Recovery".
>
> If we don't clear PxCI on error recovery, the previous command will
> incorrectly still be marked as pending after error recovery.
>
> Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>

ACK.

> ---
>  hw/ide/ahci.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
> index 366929132b..2a59d0e0f5 100644
> --- a/hw/ide/ahci.c
> +++ b/hw/ide/ahci.c
> @@ -329,6 +329,11 @@ static void ahci_port_write(AHCIState *s, int port, int offset, uint32_t val)
>          ahci_check_irq(s);
>          break;
>      case AHCI_PORT_REG_CMD:
> +        if ((pr->cmd & PORT_CMD_START) && !(val & PORT_CMD_START)) {
> +            pr->scr_act = 0;
> +            pr->cmd_issue = 0;
> +        }
> +
>          /* Block any Read-only fields from being set;
>           * including LIST_ON and FIS_ON.
>           * The spec requires to set ICC bits to zero after the ICC change
> --
> 2.40.0
>