| Message ID | 20201001084425.23117-4-rojay@codeaurora.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Implement Shutdown callback for geni-i2c | expand |
Quoting Roja Rani Yarubandi (2020-10-01 01:44:25) > diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c > index aee2a1dd2c62..56d3fbfe7eb6 100644 > --- a/drivers/i2c/busses/i2c-qcom-geni.c > +++ b/drivers/i2c/busses/i2c-qcom-geni.c > @@ -380,6 +380,36 @@ static void geni_i2c_tx_msg_cleanup(struct geni_i2c_dev *gi2c, > } > } > > +static void geni_i2c_stop_xfer(struct geni_i2c_dev *gi2c) > +{ > + int ret; > + u32 geni_status; > + unsigned long flags; > + struct i2c_msg *cur; > + > + /* Resume device, runtime suspend can happen anytime during transfer */ > + ret = pm_runtime_get_sync(gi2c->se.dev); > + if (ret < 0) { > + dev_err(gi2c->se.dev, "Failed to resume device: %d\n", ret); > + return; > + } > + > + spin_lock_irqsave(&gi2c->lock, flags); We grab the lock here. > + geni_status = readl_relaxed(gi2c->se.base + SE_GENI_STATUS); > + if (!(geni_status & M_GENI_CMD_ACTIVE)) > + goto out; > + > + cur = gi2c->cur; > + geni_i2c_abort_xfer(gi2c); But it looks like this function takes the lock again? Did you test this with lockdep enabled? It should hang even without lockdep, so it seems like this path of code has not been tested. > + if (cur->flags & I2C_M_RD) > + geni_i2c_rx_msg_cleanup(gi2c, cur); > + else > + geni_i2c_tx_msg_cleanup(gi2c, cur); > + spin_unlock_irqrestore(&gi2c->lock, flags); > +out: > + pm_runtime_put_sync_suspend(gi2c->se.dev); > +} > + > static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, > u32 m_param) > {
Hi Stephen, On 2020-10-03 07:09, Stephen Boyd wrote: > Quoting Roja Rani Yarubandi (2020-10-01 01:44:25) >> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c >> b/drivers/i2c/busses/i2c-qcom-geni.c >> index aee2a1dd2c62..56d3fbfe7eb6 100644 >> --- a/drivers/i2c/busses/i2c-qcom-geni.c >> +++ b/drivers/i2c/busses/i2c-qcom-geni.c >> @@ -380,6 +380,36 @@ static void geni_i2c_tx_msg_cleanup(struct >> geni_i2c_dev *gi2c, >> } >> } >> >> +static void geni_i2c_stop_xfer(struct geni_i2c_dev *gi2c) >> +{ >> + int ret; >> + u32 geni_status; >> + unsigned long flags; >> + struct i2c_msg *cur; >> + >> + /* Resume device, runtime suspend can happen anytime during >> transfer */ >> + ret = pm_runtime_get_sync(gi2c->se.dev); >> + if (ret < 0) { >> + dev_err(gi2c->se.dev, "Failed to resume device: %d\n", >> ret); >> + return; >> + } >> + >> + spin_lock_irqsave(&gi2c->lock, flags); > > We grab the lock here. > >> + geni_status = readl_relaxed(gi2c->se.base + SE_GENI_STATUS); >> + if (!(geni_status & M_GENI_CMD_ACTIVE)) >> + goto out; >> + >> + cur = gi2c->cur; >> + geni_i2c_abort_xfer(gi2c); > > But it looks like this function takes the lock again? Did you test this > with lockdep enabled? It should hang even without lockdep, so it seems > like this path of code has not been tested. > Tested with lockdep enabled, and fixed the unsafe lock order issue here. And to be more proper moved spin_lock/unlock to cleanup functions. >> + if (cur->flags & I2C_M_RD) >> + geni_i2c_rx_msg_cleanup(gi2c, cur); >> + else >> + geni_i2c_tx_msg_cleanup(gi2c, cur); >> + spin_unlock_irqrestore(&gi2c->lock, flags); >> +out: >> + pm_runtime_put_sync_suspend(gi2c->se.dev); >> +} >> + >> static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct >> i2c_msg *msg, >> u32 m_param) >> {
diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c index aee2a1dd2c62..56d3fbfe7eb6 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -380,6 +380,36 @@ static void geni_i2c_tx_msg_cleanup(struct geni_i2c_dev *gi2c, } } +static void geni_i2c_stop_xfer(struct geni_i2c_dev *gi2c) +{ + int ret; + u32 geni_status; + unsigned long flags; + struct i2c_msg *cur; + + /* Resume device, runtime suspend can happen anytime during transfer */ + ret = pm_runtime_get_sync(gi2c->se.dev); + if (ret < 0) { + dev_err(gi2c->se.dev, "Failed to resume device: %d\n", ret); + return; + } + + spin_lock_irqsave(&gi2c->lock, flags); + geni_status = readl_relaxed(gi2c->se.base + SE_GENI_STATUS); + if (!(geni_status & M_GENI_CMD_ACTIVE)) + goto out; + + cur = gi2c->cur; + geni_i2c_abort_xfer(gi2c); + if (cur->flags & I2C_M_RD) + geni_i2c_rx_msg_cleanup(gi2c, cur); + else + geni_i2c_tx_msg_cleanup(gi2c, cur); + spin_unlock_irqrestore(&gi2c->lock, flags); +out: + pm_runtime_put_sync_suspend(gi2c->se.dev); +} + static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, u32 m_param) { @@ -661,6 +691,13 @@ static int geni_i2c_remove(struct platform_device *pdev) return 0; } +static void geni_i2c_shutdown(struct platform_device *pdev) +{ + struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev); + + geni_i2c_stop_xfer(gi2c); +} + static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev) { int ret; @@ -725,6 +762,7 @@ MODULE_DEVICE_TABLE(of, geni_i2c_dt_match); static struct platform_driver geni_i2c_driver = { .probe = geni_i2c_probe, .remove = geni_i2c_remove, + .shutdown = geni_i2c_shutdown, .driver = { .name = "geni_i2c", .pm = &geni_i2c_pm_ops,
If the hardware is still accessing memory after SMMU translation is disabled (as part of smmu shutdown callback), then the IOVAs (I/O virtual address) which it was using will go on the bus as the physical addresses which will result in unknown crashes like NoC/interconnect errors. So, implement shutdown callback to i2c driver to stop on-going transfer and unmap DMA mappings during system "reboot" or "shutdown". Fixes: 37692de5d523 ("i2c: i2c-qcom-geni: Add bus driver for the Qualcomm GENI I2C controller") Signed-off-by: Roja Rani Yarubandi <rojay@codeaurora.org> --- Changes in V2: - As per Stephen's comments added seperate function for stop transfer, fixed minor nitpicks. - As per Stephen's comments, changed commit text. Changes in V3: - As per Stephen's comments, squashed patch 1 into patch 2, added Fixes tag. - As per Akash's comments, included FIFO case in stop_xfer, fixed minor nitpicks. Changes in V4: - As per Stephen's comments cleaned up geni_i2c_stop_xfer function, added dma_buf in geni_i2c_dev struct to call i2c_put_dma_safe_msg_buf() from other functions, removed "iova" check in geni_se_rx_dma_unprep() and geni_se_tx_dma_unprep() functions. - Added two helper functions geni_i2c_rx_one_msg_done() and geni_i2c_tx_one_msg_done() to unwrap the things after rx/tx FIFO/DMA transfers, so that the same can be used in geni_i2c_stop_xfer() function during shutdown callback. Updated commit text accordingly. - Checking whether it is tx/rx transfer using I2C_M_RD which is valid for both FIFO and DMA cases, so dropped DMA_RX_ACTIVE and DMA_TX_ACTIVE bit checking Changes in V5: - As per Stephen's comments, added spin_lock_irqsave & spin_unlock_irqsave in geni_i2c_stop_xfer() function. drivers/i2c/busses/i2c-qcom-geni.c | 38 ++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+)