| Message ID | 20221207055435.30557-1-bayi.cheng@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] spi: spi-mtk-nor: Add recovery mechanism for dma read timeout | expand |
Il 07/12/22 06:54, Bayi Cheng ha scritto: > From: bayi cheng <bayi.cheng@mediatek.com> > > The state machine of MTK spi nor controller may be disturbed by some > glitch signals from the relevant BUS during dma read, Although the > possibility of causing the dma read to fail is next to nothing, > However, if error-handling is not implemented, which makes the feature > somewhat risky. > > Add an error-handling mechanism here, reset the state machine and > re-read the data when an error occurs. > > Signed-off-by: bayi cheng <bayi.cheng@mediatek.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
On Wed, 07 Dec 2022 13:54:35 +0800, Bayi Cheng wrote: > The state machine of MTK spi nor controller may be disturbed by some > glitch signals from the relevant BUS during dma read, Although the > possibility of causing the dma read to fail is next to nothing, > However, if error-handling is not implemented, which makes the feature > somewhat risky. > > Add an error-handling mechanism here, reset the state machine and > re-read the data when an error occurs. > > [...] Applied to https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next Thanks! [1/1] spi: spi-mtk-nor: Add recovery mechanism for dma read timeout commit: 8330e9e8269bb76dd502e84efb5f351016512cf8 All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark
diff --git a/drivers/spi/spi-mtk-nor.c b/drivers/spi/spi-mtk-nor.c index d167699a1a96..d07f50337f43 100644 --- a/drivers/spi/spi-mtk-nor.c +++ b/drivers/spi/spi-mtk-nor.c @@ -80,6 +80,9 @@ #define MTK_NOR_REG_DMA_FADR 0x71c #define MTK_NOR_REG_DMA_DADR 0x720 #define MTK_NOR_REG_DMA_END_DADR 0x724 +#define MTK_NOR_REG_CG_DIS 0x728 +#define MTK_NOR_SFC_SW_RST BIT(2) + #define MTK_NOR_REG_DMA_DADR_HB 0x738 #define MTK_NOR_REG_DMA_END_DADR_HB 0x73c @@ -147,6 +150,15 @@ static inline int mtk_nor_cmd_exec(struct mtk_nor *sp, u32 cmd, ulong clk) return ret; } +static void mtk_nor_reset(struct mtk_nor *sp) +{ + mtk_nor_rmw(sp, MTK_NOR_REG_CG_DIS, 0, MTK_NOR_SFC_SW_RST); + mb(); /* flush previous writes */ + mtk_nor_rmw(sp, MTK_NOR_REG_CG_DIS, MTK_NOR_SFC_SW_RST, 0); + mb(); /* flush previous writes */ + writel(MTK_NOR_ENABLE_SF_CMD, sp->base + MTK_NOR_REG_WP); +} + static void mtk_nor_set_addr(struct mtk_nor *sp, const struct spi_mem_op *op) { u32 addr = op->addr.val; @@ -616,7 +628,15 @@ static int mtk_nor_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) mtk_nor_set_addr(sp, op); return mtk_nor_read_pio(sp, op); } else { - return mtk_nor_read_dma(sp, op); + ret = mtk_nor_read_dma(sp, op); + if (unlikely(ret)) { + /* Handle rare bus glitch */ + mtk_nor_reset(sp); + mtk_nor_setup_bus(sp, op); + return mtk_nor_read_dma(sp, op); + } + + return ret; } }