mtd: rawnand: meson: invalidate cache on polling ECC bit

'info_buf' memory is cached and driver polls ECC bit in it. This bit
is set by the NAND controller. If 'usleep_range()' returns before device
sets this bit, 'info_buf' will be cached and driver won't see update of
this bit and will loop forever.

Fixes: 8fae856c5350 ("mtd: rawnand: meson: add support for Amlogic NAND flash controller")
Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/d4ef0bd6-816e-f6fa-9385-f05f775f0ae2@sberdevices.ru

diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
index 30e326adabfc1ae7b15b8db815d6940833237856..a28574c009003f74b96edd0f0e31b5a4aec846d5 100644 (file)
--- a/drivers/mtd/nand/raw/meson_nand.c
+++ b/drivers/mtd/nand/raw/meson_nand.c
@@ -176,6 +176,7 @@ struct meson_nfc {
 
        dma_addr_t daddr;
        dma_addr_t iaddr;
+       u32 info_bytes;
 
        unsigned long assigned_cs;
 };
@@ -503,6 +504,7 @@ static int meson_nfc_dma_buffer_setup(struct nand_chip *nand, void *databuf,
                                         nfc->daddr, datalen, dir);
                        return ret;
                }
+               nfc->info_bytes = infolen;
                cmd = GENCMDIADDRL(NFC_CMD_AIL, nfc->iaddr);
                writel(cmd, nfc->reg_base + NFC_REG_CMD);
 
@@ -520,8 +522,10 @@ static void meson_nfc_dma_buffer_release(struct nand_chip *nand,
        struct meson_nfc *nfc = nand_get_controller_data(nand);
 
        dma_unmap_single(nfc->dev, nfc->daddr, datalen, dir);
-       if (infolen)
+       if (infolen) {
                dma_unmap_single(nfc->dev, nfc->iaddr, infolen, dir);
+               nfc->info_bytes = 0;
+       }
 }
 
 static int meson_nfc_read_buf(struct nand_chip *nand, u8 *buf, int len)
@@ -710,6 +714,8 @@ static void meson_nfc_check_ecc_pages_valid(struct meson_nfc *nfc,
                usleep_range(10, 15);
                /* info is updated by nfc dma engine*/
                smp_rmb();
+               dma_sync_single_for_cpu(nfc->dev, nfc->iaddr, nfc->info_bytes,
+                                       DMA_FROM_DEVICE);
                ret = *info & ECC_COMPLETE;
        } while (!ret);
 }