On Thu, Jan 18, 2024 at 11:53:51AM -0800, dregan@xxxxxxxxxxxx wrote:
> diff --git a/drivers/mtd/nand/raw/brcmnand/bcmbca_nand.c b/drivers/mtd/nand/raw/brcmnand/bcmbca_nand.c
> index 3e2f3b79788d..e97e13ae246c 100644
> --- a/drivers/mtd/nand/raw/brcmnand/bcmbca_nand.c
> +++ b/drivers/mtd/nand/raw/brcmnand/bcmbca_nand.c
> @@ -26,6 +26,18 @@ enum {
> BCMBCA_CTLRDY = BIT(4),
> };
>
> +#if defined(CONFIG_ARM64)
> +#define ALIGN_REQ 8
> +#else
> +#define ALIGN_REQ 4
> +#endif
> +
> +static inline bool bcmbca_nand_is_buf_aligned(void *flash_cache, void *buffer)
> +{
> + return IS_ALIGNED((uintptr_t)buffer, ALIGN_REQ) &&
> + IS_ALIGNED((uintptr_t)flash_cache, ALIGN_REQ);
> +}
> +
> static bool bcmbca_nand_intc_ack(struct brcmnand_soc *soc)
> {
> struct bcmbca_nand_soc *priv =
> @@ -56,6 +68,20 @@ static void bcmbca_nand_intc_set(struct brcmnand_soc *soc, bool en)
> brcmnand_writel(val, mmio);
> }
>
> +static void bcmbca_read_data_bus(struct brcmnand_soc *soc,
> + void __iomem *flash_cache, u32 *buffer, int fc_words)
> +{
> + /*
> + * memcpy can do unaligned aligned access depending on source
> + * and dest address, which is incompatible with nand cache. Fallback
> + * to the memcpy for io version
> + */
> + if (bcmbca_nand_is_buf_aligned((void *)flash_cache, buffer))
> + memcpy((void *)buffer, (void *)flash_cache, fc_words * 4);
> + else
> + memcpy_fromio((void *)buffer, flash_cache, fc_words * 4);
> +}
This comment is confusing or maybe the if statement is reversed...
We're falling back to memcpy_fromio() for the unaligned accesses but the
comment says we're falling back to memcpy().
regards,
dan carpenter
