diff options
| author | Chuanhong Guo <gch981213@gmail.com> | 2020-09-22 19:49:02 +0800 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2020-09-25 21:40:20 +0100 |
| commit | 4cafaddedb5fbef9531202ee547784409fd0de33 (patch) | |
| tree | 05d0630df3338599fd36794f8df4039a98f3b575 /drivers/spi/spi-mtk-nor.c | |
| parent | f09a433b1e4057e6379b7e1207548fff30d5dca3 (diff) | |
| download | linux-4cafaddedb5fbef9531202ee547784409fd0de33.tar.gz | |
spi: spi-mtk-nor: fix timeout calculation overflow
CLK_TO_US macro is used to calculate potential transfer time for various
timeout handling. However it overflows on transfer bigger than 512 bytes
because it first did (len * 8 * 1000000).
This controller typically operates at 45MHz. This patch did 2 things:
1. calculate clock / 1000000 first
2. add a 4M transfer size cap so that the final timeout in DMA reading
doesn't overflow
Fixes: 881d1ee9fe81f ("spi: add support for mediatek spi-nor controller")
Cc: <stable@vger.kernel.org>
Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
Link: https://lore.kernel.org/r/20200922114905.2942859-1-gch981213@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-mtk-nor.c')
| -rw-r--r-- | drivers/spi/spi-mtk-nor.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/spi/spi-mtk-nor.c b/drivers/spi/spi-mtk-nor.c index 6e6ca2b8e6c8..62f5ff277988 100644 --- a/drivers/spi/spi-mtk-nor.c +++ b/drivers/spi/spi-mtk-nor.c @@ -89,7 +89,7 @@ // Buffered page program can do one 128-byte transfer #define MTK_NOR_PP_SIZE 128 -#define CLK_TO_US(sp, clkcnt) ((clkcnt) * 1000000 / sp->spi_freq) +#define CLK_TO_US(sp, clkcnt) DIV_ROUND_UP(clkcnt, sp->spi_freq / 1000000) struct mtk_nor { struct spi_controller *ctlr; @@ -177,6 +177,10 @@ static int mtk_nor_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op) if ((op->addr.nbytes == 3) || (op->addr.nbytes == 4)) { if ((op->data.dir == SPI_MEM_DATA_IN) && mtk_nor_match_read(op)) { + // limit size to prevent timeout calculation overflow + if (op->data.nbytes > 0x400000) + op->data.nbytes = 0x400000; + if ((op->addr.val & MTK_NOR_DMA_ALIGN_MASK) || (op->data.nbytes < MTK_NOR_DMA_ALIGN)) op->data.nbytes = 1; |