Mika,
Would you please add your Acked-by again? It's dropped in v4.
Looks good for me, below is my R-b.
Thanks!
On 03/19/2019 07:18 PM, Sverdlin, Alexander (Nokia - DE/Ulm) wrote:
> External E-Mail
>
>
> From: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx>
>
> 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.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Reported-by: Romain Porte <romain.porte@xxxxxxxxx>
> Tested-by: Pascal Fabreges <pascal.fabreges@xxxxxxxxx>
> Signed-off-by: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx>
Reviewed-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
> ---
> Changelog:
> v2: More macros! As suggested by Mika.
> v3: Actually compiled. Sorry Mika, the lines are really long now.
> v4: Add "mtd:" to the subject
>
> 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);
>
