Re: [Qemu-devel] [PATCH 3/3] sdhci: add optional quirk property to disable card insertion/removal interrupts

[Peter Crosthwaite <crosthwaitepeter@gmail.com>]

On Wed, Dec 16, 2015 at 11:47 AM, Andrew Baumann
<Andrew.Baumann@microsoft.com> wrote:
> This is needed for a quirk of the Raspberry Pi (bcm2835/6) MMC
> controller, where the card insert bit is documented as unimplemented
> (always reads zero, doesn't generate interrupts) but is in fact
> observed on hardware as set at power on, but is cleared (and remains
> clear) on subsequent controller resets.
>

Yep. Thats what the doc is saying.

FWIW , that set-on-reset behaviour makes me very suspicious that this
is the SoC layer or pin mux tying off this pin incorrectly. A bug in
the pin-mux would cause exactly this symptom.

Unfortunately we (or at least I) don't have access to Arasan's doc to
tell if this this is SoC errata or SDHCI errata and the Broadcom doc
quite unhelpfully refers the reader to:

sd3.0_host_ahb_emmc4.4_usersguide_ver5.9_jan11_10.pdf

Which doesn't google.

> Signed-off-by: Andrew Baumann <Andrew.Baumann@microsoft.com>

Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>

> ---
>  hw/sd/sdhci.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
> index dd83e89..61f919b 100644
> --- a/hw/sd/sdhci.c
> +++ b/hw/sd/sdhci.c
> @@ -193,7 +193,9 @@ static void sdhci_reset(SDHCIState *s)
>       * initialization */
>      memset(&s->sdmasysad, 0, (uintptr_t)&s->capareg - (uintptr_t)&s->sdmasysad);
>
> -    sd_set_cb(s->card, s->ro_cb, s->eject_cb);
> +    if (!s->noeject_quirk) {
> +        sd_set_cb(s->card, s->ro_cb, s->eject_cb);
> +    }

This will conflict with PMMs SD busification work but the resolution
should be reasonably straightforward. The Busifed SDHCI can chose to
ignore the inserted cb from the bus instead of the card.

Regards,
Peter

>      s->data_count = 0;
>      s->stopped_state = sdhc_not_stopped;
>  }
> @@ -1208,6 +1210,7 @@ const VMStateDescription sdhci_vmstate = {
>          VMSTATE_UINT16(data_count, SDHCIState),
>          VMSTATE_UINT64(admasysaddr, SDHCIState),
>          VMSTATE_UINT8(stopped_state, SDHCIState),
> +        VMSTATE_BOOL(noeject_quirk, SDHCIState),
>          VMSTATE_VBUFFER_UINT32(fifo_buffer, SDHCIState, 1, NULL, 0, buf_maxsz),
>          VMSTATE_TIMER_PTR(insert_timer, SDHCIState),
>          VMSTATE_TIMER_PTR(transfer_timer, SDHCIState),
> @@ -1276,6 +1279,7 @@ static Property sdhci_sysbus_properties[] = {
>      DEFINE_PROP_UINT32("capareg", SDHCIState, capareg,
>              SDHC_CAPAB_REG_DEFAULT),
>      DEFINE_PROP_UINT32("maxcurr", SDHCIState, maxcurr, 0),
> +    DEFINE_PROP_BOOL("noeject-quirk", SDHCIState, noeject_quirk, false),
>      DEFINE_PROP_END_OF_LIST(),
>  };
>
> --
> 2.5.3
>