From 2b75ebeea6f4937d4d05ec4982c471cef9a29b7f Mon Sep 17 00:00:00 2001 From: Alexander Sverdlin Date: Tue, 19 Mar 2019 17:18:07 +0000 Subject: [PATCH] mtd: spi-nor: intel-spi: Avoid crossing 4K address boundary on read/write It was observed that reads crossing 4K address boundary are failing. This limitation is mentioned in Intel documents: Intel(R) 9 Series Chipset Family Platform Controller Hub (PCH) Datasheet: "5.26.3 Flash Access Program Register Access: * Program Register Accesses are not allowed to cross a 4 KB boundary..." Enhanced Serial Peripheral Interface (eSPI) Interface Base Specification (for Client and Server Platforms): "5.1.4 Address For other memory transactions, the address may start or end at any byte boundary. However, the address and payload length combination must not cross the naturally aligned address boundary of the corresponding Maximum Payload Size. It must not cross a 4 KB address boundary." Avoid this by splitting an operation crossing the boundary into two operations. Fixes: 8afda8b26d01 ("spi-nor: Add support for Intel SPI serial flash controller") Cc: stable@vger.kernel.org Reported-by: Romain Porte Tested-by: Pascal Fabreges Signed-off-by: Alexander Sverdlin Reviewed-by: Tudor Ambarus Acked-by: Mika Westerberg Signed-off-by: Miquel Raynal --- drivers/mtd/spi-nor/intel-spi.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/mtd/spi-nor/intel-spi.c b/drivers/mtd/spi-nor/intel-spi.c index af0a220..d60cbf2 100644 --- a/drivers/mtd/spi-nor/intel-spi.c +++ b/drivers/mtd/spi-nor/intel-spi.c @@ -632,6 +632,10 @@ static ssize_t intel_spi_read(struct spi_nor *nor, loff_t from, size_t len, while (len > 0) { block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ); + /* Read cannot cross 4K boundary */ + block_size = min_t(loff_t, from + block_size, + round_up(from + 1, SZ_4K)) - from; + writel(from, ispi->base + FADDR); val = readl(ispi->base + HSFSTS_CTL); @@ -685,6 +689,10 @@ static ssize_t intel_spi_write(struct spi_nor *nor, loff_t to, size_t len, while (len > 0) { block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ); + /* Write cannot cross 4K boundary */ + block_size = min_t(loff_t, to + block_size, + round_up(to + 1, SZ_4K)) - to; + writel(to, ispi->base + FADDR); val = readl(ispi->base + HSFSTS_CTL); -- 2.7.4