Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 10cd4b7b authored by Ludovic Barre's avatar Ludovic Barre Committed by Cyrille Pitchen
Browse files

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: default avatarLudovic Barre <ludovic.barre@st.com>
Reported-by: default avatarBruno Herrera <bruherrera@gmail.com>
Tested-by: default avatarBruno Herrera <bruherrera@gmail.com>
Signed-off-by: default avatarCyrille Pitchen <cyrille.pitchen@wedev4u.fr>
parent e812963b

drivers/mtd/spi-nor/stm32-quadspi.c

+11 −1
Original line number Diff line number Diff line
@@ -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 @@ static int stm32_qspi_send(struct stm32_qspi_flash *flash, 
	cr = readl_relaxed(qspi->io_base + QUADSPI_CR) | CR_ABORT;

	writel_relaxed(cr, qspi->io_base + QUADSPI_CR);



	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)