Re: [PATCH] hw/sd/sdhci: Do not force sdhci_mmio_*_ops onto all SD controllers

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 9/7/23 10:09, Bernhard Beschow wrote:
> Since commit c0a55a0c9da2 "hw/sd/sdhci: Support big endian SD host controller
> interfaces" sdhci_common_realize() forces all SD card controllers to use either
> sdhci_mmio_le_ops or sdhci_mmio_be_ops, depending on the "endianness" property.
> However, there are device models which use different MMIO ops: TYPE_IMX_USDHC
> uses usdhc_mmio_ops and TYPE_S3C_SDHCI uses sdhci_s3c_mmio_ops.
> 
> Forcing sdhci_mmio_le_ops breaks SD card handling on the "sabrelite" board, for
> example. Fix this by defaulting the io_ops to little endian and switch to big
> endian in sdhci_common_realize() only if there is a matchig big endian variant
> available.
> 
> Fixes: c0a55a0c9da2 ("hw/sd/sdhci: Support big endian SD host controller
> interfaces")
> 
> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
> ---
>   hw/sd/sdhci.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
> index 6811f0f1a8..362c2c86aa 100644
> --- a/hw/sd/sdhci.c
> +++ b/hw/sd/sdhci.c
> @@ -1382,6 +1382,8 @@ void sdhci_initfn(SDHCIState *s)
>   
>       s->insert_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, sdhci_raise_insertion_irq, s);
>       s->transfer_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, sdhci_data_transfer, s);
> +
> +    s->io_ops = &sdhci_mmio_le_ops;
>   }
>   
>   void sdhci_uninitfn(SDHCIState *s)
> @@ -1399,9 +1401,13 @@ void sdhci_common_realize(SDHCIState *s, Error **errp)
>   

What about simply keeping the same code guarded with 'if (!s->io_ops)'?

>       switch (s->endianness) {
>       case DEVICE_LITTLE_ENDIAN:
> -        s->io_ops = &sdhci_mmio_le_ops;
> +        /* s->io_ops is little endian by default */
>           break;
>       case DEVICE_BIG_ENDIAN:
> +        if (s->io_ops != &sdhci_mmio_le_ops) {
> +            error_setg(errp, "SD controller doesn't support big endianness");
> +            return;
> +        }
>           s->io_ops = &sdhci_mmio_be_ops;
>           break;
>       default: