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authorLudovic Barre <ludovic.barre@st.com>2017-10-26 17:12:34 +0200
committerCyrille Pitchen <cyrille.pitchen@wedev4u.fr>2017-10-29 18:54:22 +0100
commit10cd4b7b7432d529d7f8b73979a846e33a573a9e (patch)
tree4827aa1a6ffef13bcf6ba4f146f9c4831eab03dc /drivers/mtd/spi-nor
parente812963b918656d875beb47c277fd0e29bd826af (diff)
downloadlinux-10cd4b7b7432d529d7f8b73979a846e33a573a9e.tar.bz2
mtd: spi-nor: stm32-quadspi: fix prefetching outside fsize
When memory-mapped mode is used, a prefetching mechanism fully managed by the hardware allows to optimize the read from external the QSPI memory. A 32-bytes FIFO is used for prefetching. When the limit of flash size - fifo size is reached the prefetching mechanism tries to read outside the fsize. The stm32 quadspi hardware become busy and should be aborted. Signed-off-by: Ludovic Barre <ludovic.barre@st.com> Reported-by: Bruno Herrera <bruherrera@gmail.com> Tested-by: Bruno Herrera <bruherrera@gmail.com> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>
Diffstat (limited to 'drivers/mtd/spi-nor')
-rw-r--r--drivers/mtd/spi-nor/stm32-quadspi.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/mtd/spi-nor/stm32-quadspi.c b/drivers/mtd/spi-nor/stm32-quadspi.c
index 56b75fc226c3..b3c7f6addba7 100644
--- a/drivers/mtd/spi-nor/stm32-quadspi.c
+++ b/drivers/mtd/spi-nor/stm32-quadspi.c
@@ -126,6 +126,7 @@
#define STM32_MAX_MMAP_SZ SZ_256M
#define STM32_MAX_NORCHIP 2
+#define STM32_QSPI_FIFO_SZ 32
#define STM32_QSPI_FIFO_TIMEOUT_US 30000
#define STM32_QSPI_BUSY_TIMEOUT_US 100000
@@ -137,6 +138,7 @@ struct stm32_qspi_flash {
u32 presc;
u32 read_mode;
bool registered;
+ u32 prefetch_limit;
};
struct stm32_qspi {
@@ -285,6 +287,7 @@ static int stm32_qspi_send(struct stm32_qspi_flash *flash,
{
struct stm32_qspi *qspi = flash->qspi;
u32 ccr, dcr, cr;
+ u32 last_byte;
int err;
err = stm32_qspi_wait_nobusy(qspi);
@@ -327,6 +330,10 @@ static int stm32_qspi_send(struct stm32_qspi_flash *flash,
if (err)
goto abort;
writel_relaxed(FCR_CTCF, qspi->io_base + QUADSPI_FCR);
+ } else {
+ last_byte = cmd->addr + cmd->len;
+ if (last_byte > flash->prefetch_limit)
+ goto abort;
}
return err;
@@ -335,7 +342,9 @@ abort:
cr = readl_relaxed(qspi->io_base + QUADSPI_CR) | CR_ABORT;
writel_relaxed(cr, qspi->io_base + QUADSPI_CR);
- dev_err(qspi->dev, "%s abort err:%d\n", __func__, err);
+ if (err)
+ dev_err(qspi->dev, "%s abort err:%d\n", __func__, err);
+
return err;
}
@@ -563,6 +572,7 @@ static int stm32_qspi_flash_setup(struct stm32_qspi *qspi,
}
flash->fsize = FSIZE_VAL(mtd->size);
+ flash->prefetch_limit = mtd->size - STM32_QSPI_FIFO_SZ;
flash->read_mode = CCR_FMODE_MM;
if (mtd->size > qspi->mm_size)