| Message ID | 20201221123801.26643-3-rojay@codeaurora.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Implement Shutdown callback for geni-i2c | expand |
On 12/21/2020 6:08 PM, Roja Rani Yarubandi wrote: > 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> Reviewed-by: Akash Asthana <akashast@codeaurora.org>
> + 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); > +out: > + pm_runtime_put_sync_suspend(gi2c->se.dev); > +} The use of 'goto' is not needed here IMHO. I think: if (geni_status & M_GENI_CMD_ACTIVE) { do_the_stuff } pm_runtime_put_sync_suspend(...); is more readable, in fact. Also, I don't think we really need the 'cur' variable and just use 'gi2c->cur' but that's very minor and you can keep it if you like it. Reset looks good!
Hi Wolfram, On 2021-01-05 20:57, Wolfram Sang wrote: >> + 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); >> +out: >> + pm_runtime_put_sync_suspend(gi2c->se.dev); >> +} > > The use of 'goto' is not needed here IMHO. I think: > > if (geni_status & M_GENI_CMD_ACTIVE) { > do_the_stuff > } > > pm_runtime_put_sync_suspend(...); > > is more readable, in fact. > In context to the previous comment [1], I have implemented this way. But, yeah anything is fine for me. > Also, I don't think we really need the 'cur' > variable and just use 'gi2c->cur' but that's very minor and you can > keep > it if you like it. > In geni_i2c_abort_xfer() function gi2c->cur will be made NULL, so copying it before to "cur" is needed here. > Reset looks good! [1] https://patchwork.kernel.org/project/linux-arm-msm/patch/20200820103522.26242-3-rojay@codeaurora.org/#23560541 Thanks, Roja
> > The use of 'goto' is not needed here IMHO. I think: ... > In context to the previous comment [1], I have implemented this way. > But, yeah anything is fine for me. Thanks, I really think it is better. > In geni_i2c_abort_xfer() function gi2c->cur will be made NULL, so copying it > before to "cur" is needed here. Okay then, thanks for the heads up!
diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c index 214b4c913a13..7903e6145543 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -375,6 +375,33 @@ 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; + struct i2c_msg *cur; + + /* Resume device, as 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; + } + + 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); +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) { @@ -650,6 +677,13 @@ 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; @@ -714,6 +748,7 @@ 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. Changes in V6: - As per Stephen's comments, taken care of unsafe lock order in geni_i2c_stop_xfer(). - Moved spin_lock/unlock to geni_i2c_rx_msg_cleanup() and geni_i2c_tx_msg_cleanup() functions. Changes in V7: - No changes drivers/i2c/busses/i2c-qcom-geni.c | 35 ++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+)