Messages in this thread | | | Date | Thu, 20 Aug 2020 16:00:33 +0530 | From | rojay@codeauro ... | Subject | Re: [PATCH 2/2] i2c: i2c-qcom-geni: Add shutdown callback for i2c |
| |
On 2020-08-19 09:13, Stephen Boyd wrote: > Quoting Roja Rani Yarubandi (2020-08-14 02:55:40) >> If the hardware is still accessing memory after SMMU translation >> is disabled(as part of smmu shutdown callback), then the > > Put a space before ( >
Ok.
>> IOVAs(I/O virtual address) which it was using will go on the bus > > Put a space before ( > >> as the physical addresses which will result in unknown crashes >> like NoC/interconnect errors. >> >> So, adding shutdown callback to i2c driver to unmap DMA mappings >> during system "reboot" or "shutdown". >> > > Deserves a Fixes: tag if it's fixing a problem, which it looks like it > is. >
It is not fixing a problem. We are anticipating a problem and implementing Shutdown callback.
>> Signed-off-by: Roja Rani Yarubandi <rojay@codeaurora.org> >> --- >> drivers/i2c/busses/i2c-qcom-geni.c | 36 >> ++++++++++++++++++++++++++++++ >> include/linux/qcom-geni-se.h | 5 +++++ > > I'd prefer this is squashed with the previous patch. The first patch > doesn't really stand on its own anyway. >
Sorry, I did not understand. First patch can be compiled independently.
>> 2 files changed, 41 insertions(+) >> >> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c >> b/drivers/i2c/busses/i2c-qcom-geni.c >> index 53ca41f76080..749c225f95c4 100644 >> --- a/drivers/i2c/busses/i2c-qcom-geni.c >> +++ b/drivers/i2c/busses/i2c-qcom-geni.c >> @@ -613,6 +613,41 @@ static int geni_i2c_remove(struct platform_device >> *pdev) >> return 0; >> } >> >> +static void geni_i2c_shutdown(struct platform_device *pdev) >> +{ >> + int ret; >> + struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev); >> + struct geni_se *se = &gi2c->se; >> + u32 dma; >> + u32 dma_dbg_reg; > > Typically this is just called 'val'. >
Ok.
>> + >> + ret = pm_runtime_get_sync(gi2c->se.dev); >> + if (ret < 0) { >> + dev_err(gi2c->se.dev, "Failed to resume device:%d\n", >> ret); > > Maybe just write: "Failed to resume device\n"? Not sure anyone cares > what the error code is. And if they did, it would be connected to the > colon so it will be hard to read. Add a space after colon if you want > to > keep the return value please. >
Ok, will add space after colon.
>> + return; >> + } >> + >> + dma = readl_relaxed(se->base + SE_GENI_DMA_MODE_EN); >> + if (dma) { >> + dma_dbg_reg = readl_relaxed(gi2c->se.base + >> SE_DMA_DEBUG_REG0); >> + if (dma_dbg_reg & DMA_TX_ACTIVE) { >> + geni_i2c_abort_xfer(gi2c); >> + gi2c->cur_wr = 0; >> + if (gi2c->err) >> + geni_i2c_tx_fsm_rst(gi2c); >> + geni_se_tx_dma_unprep(se, gi2c->tx_dma, >> gi2c->xfer_len); >> + } >> + if (dma_dbg_reg & DMA_RX_ACTIVE) { >> + geni_i2c_abort_xfer(gi2c); >> + gi2c->cur_rd = 0; >> + if (gi2c->err) >> + geni_i2c_rx_fsm_rst(gi2c); >> + geni_se_rx_dma_unprep(se, gi2c->rx_dma, >> gi2c->xfer_len); >> + } > > Can this be a function? It sort of seems like we should be doing the > same sort of stuff if we're canceling a DMA transaction in flight. >
Ok. Will make the changes.
>> + } >> + pm_runtime_put_sync_suspend(gi2c->se.dev); >> +} >> + >> static int __maybe_unused geni_i2c_runtime_suspend(struct device >> *dev) >> { >> int ret; >> diff --git a/include/linux/qcom-geni-se.h >> b/include/linux/qcom-geni-se.h >> index dd464943f717..acad69be747d 100644 >> --- a/include/linux/qcom-geni-se.h >> +++ b/include/linux/qcom-geni-se.h >> @@ -77,6 +77,7 @@ struct geni_se { >> #define SE_DMA_RX_FSM_RST 0xd58 >> #define SE_HW_PARAM_0 0xe24 >> #define SE_HW_PARAM_1 0xe28 >> +#define SE_DMA_DEBUG_REG0 0xe40 >> >> /* GENI_FORCE_DEFAULT_REG fields */ >> #define FORCE_DEFAULT BIT(0) >> @@ -207,6 +208,10 @@ struct geni_se { >> #define RX_GENI_CANCEL_IRQ BIT(11) >> #define RX_GENI_GP_IRQ_EXT GENMASK(13, 12) >> >> +/* DMA DEBUG Register fields */ > > Please follow other style, ie. SE_DMA_DEBUG_REG0 fields >
Ok.
>> +#define DMA_TX_ACTIVE BIT(0) >> +#define DMA_RX_ACTIVE BIT(1) >> + >> /* SE_HW_PARAM_0 fields */ >> #define TX_FIFO_WIDTH_MSK GENMASK(29, 24) >> #define TX_FIFO_WIDTH_SHFT 24
| |