| Message ID | 20210525131051.31250-2-rojay@codeaurora.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | Implement Shutdown callback for geni_i2c | expand |
Quoting Roja Rani Yarubandi (2021-05-25 06:10:50) > 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 for i2c driver to suspend the bus > 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: Stephen Boyd <swboyd@chromium.org>
On Tue, May 25, 2021 at 06:40:50PM +0530, 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 for i2c driver to suspend the bus > 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> Do we need patch 1 after patch 2 was applied? I always thought all devices are suspended before shutdown/reboot? Nice to see that 'mark_adapter_suspended' becomes useful again!
On 2021-05-28 13:41, Wolfram Sang wrote: > On Tue, May 25, 2021 at 06:40:50PM +0530, 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 for i2c driver to suspend the bus >> 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> > > Do we need patch 1 after patch 2 was applied? I always thought all > devices are suspended before shutdown/reboot? > Yes, both patch 1 and patch 2 are required. Devices are not suspended during shutdown/reboot. > Nice to see that 'mark_adapter_suspended' becomes useful again! Thanks, Roja
On 2021-05-28 13:41, Wolfram Sang wrote: > On Tue, May 25, 2021 at 06:40:50PM +0530, 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 for i2c driver to suspend the bus >> 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> > > Do we need patch 1 after patch 2 was applied? I always thought all > devices are suspended before shutdown/reboot? > Yes, both patch 1 and patch 2 are required. Devices are not suspended during shutdown/reboot. > Nice to see that 'mark_adapter_suspended' becomes useful again! Thanks, Roja
On Tue, May 25, 2021 at 06:40:50PM +0530, 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 for i2c driver to suspend the bus > 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> Applied to for-current, thanks!
diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c index 214b4c913a13..c3ae66ba6345 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -650,6 +650,14 @@ 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); + + /* Make client i2c transfers start failing */ + i2c_mark_adapter_suspended(&gi2c->adap); +} + static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev) { int ret; @@ -714,6 +722,7 @@ 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 for i2c driver to suspend the bus 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 Changes in V8: - As per Wolfram Sang comment, removed goto and modified geni_i2c_stop_xfer() accordingly. Changes in V9: - Fixed possbile race by protecting gi2c->cur and calling geni_i2c_abort_xfer() with adding another parameter to differentiate from which sequence is the geni_i2c_abort_xfer() called and handle the spin_lock/spin_unlock accordingly inside geni_i2c_abort_xfer(). For this added two macros ABORT_XFER and STOP_AND_ABORT_XFER. - Added a bool variable "stop_xfer" in geni_i2c_dev struct, used to put stop to upcoming geni_i2c_rx_one_msg() and geni_i2c_tx_one_msg() calls once we recieve the shutdown call. - Added gi2c->cur == NULL check in geni_i2c_irq() to not to process the irq even if any transfer is queued and shutdown to HW received. Changes in V10: - As per Stephen's comments, removed ongoing transfers flush and only suspending i2c bus in shutdown callback. - Also removed all other changes which have been made for ongoing transfers flush, handling race issues etc., during shutdown callback. - Updated commit text accordingly. Changes in V11: - As per Stephen's comments, suspended bus in shutdown call using i2c_mark_adapter_suspended() call to block any future transfers. drivers/i2c/busses/i2c-qcom-geni.c | 9 +++++++++ 1 file changed, 9 insertions(+)