On 28/11/22 04:44, Doug Brown wrote:
> The PXA168 has a documented silicon bug that results in a data abort
> exception when accessing the SDHCI_HOST_VERSION register on SDH2 and
> SDH4 through a 16-bit read. Implement the workaround described in the
> errata, which performs a 32-bit read from a lower address instead. This
> is safe to use on all four SDH peripherals.
>
> Signed-off-by: Doug Brown <doug@xxxxxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-pxav2.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-pxav2.c b/drivers/mmc/host/sdhci-pxav2.c
> index 2f9fa0ecbddd..d76131b8986b 100644
> --- a/drivers/mmc/host/sdhci-pxav2.c
> +++ b/drivers/mmc/host/sdhci-pxav2.c
> @@ -80,6 +80,18 @@ static void pxav2_reset(struct sdhci_host *host, u8 mask)
> }
> }
>
> +static inline u16 pxav1_readw(struct sdhci_host *host, int reg)
> +{
> + u32 temp;
> + /* Workaround for data abort exception on SDH2 and SDH4 on PXA168 */
> + if (reg == SDHCI_HOST_VERSION) {
> + temp = readl(host->ioaddr + SDHCI_HOST_VERSION - 2) >> 16;
> + return temp & 0xffff;
Isn't this the same as just:
return readl(host->ioaddr + SDHCI_HOST_VERSION - 2) >> 16;
> + }
> +
> + return readw(host->ioaddr + reg);
> +}
> +
> static void pxav2_mmc_set_bus_width(struct sdhci_host *host, int width)
> {
> u8 ctrl;
> @@ -102,6 +114,7 @@ static void pxav2_mmc_set_bus_width(struct sdhci_host *host, int width)
> }
>
> static const struct sdhci_ops pxav1_sdhci_ops = {
> + .read_w = pxav1_readw,
> .set_clock = sdhci_set_clock,
> .get_max_clock = sdhci_pltfm_clk_get_max_clock,
> .set_bus_width = pxav2_mmc_set_bus_width,
