Hi, On 01/18/2024 09:36 PM, Dan Carpenter wrote:
Yes that's a typo. Fallback to memcpy_fromio when unalgined. Will update the comments in v3. Thanks!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
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