Re: [Qemu-block] [PATCH v1 1/2] sd: sdhci: Delete over-zealous power check

[Peter Crosthwaite]

CCing Andrew who ran into a similar issue for rPI.

On Sat, Nov 28, 2015 at 12:50 PM, Peter Crosthwaite
<address@hidden> wrote:
> This check was conditionalising SD card operation on the card being
> powered by the SDHCI host controller. It is however possible
> (particularly in embedded systems) for the power control of the SD card
> to be managed outside of SDHCI. This can be as trivial as hard-wiring
> the SD slot VCC to a constant power-rail.
>
> This means the guest SDHCI can validly opt-out of the SDHCI power
> control feature while still using the card. So delete this check to
> allow operation of the card with SDHCI power control.
>
> This is needed for at least Xilinx Zynq and also makes Freescale i.MX25
> work for me. The digilent Zybo board has a public schematic
> which shows SD VCC hardwiring:
>
> http://digilentinc.com/Data/Products/ZYBO/ZYBO_sch_VB.3.pdf
> bottom of page 3.
>
> Signed-off-by: Peter Crosthwaite <address@hidden>
> ---
>
>  hw/sd/sdhci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
> index d70d1a6..ed536ee 100644
> --- a/hw/sd/sdhci.c
> +++ b/hw/sd/sdhci.c
> @@ -831,7 +831,7 @@ static void sdhci_data_transfer(void *opaque)
>
>  static bool sdhci_can_issue_command(SDHCIState *s)
>  {
> -    if (!SDHC_CLOCK_IS_ON(s->clkcon) || !(s->pwrcon & SDHC_POWER_ON) ||
> +    if (!SDHC_CLOCK_IS_ON(s->clkcon) ||
>          (((s->prnsts & SDHC_DATA_INHIBIT) || s->stopped_state) &&
>          ((s->cmdreg & SDHC_CMD_DATA_PRESENT) ||
>          ((s->cmdreg & SDHC_CMD_RESPONSE) == SDHC_CMD_RSP_WITH_BUSY &&
> --
> 1.9.1
>