| Message ID | 20221105191954.14360-3-samuel@sholland.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | bus: sunxi-rsb: Fix poweroff issues | expand |
Dne sobota, 05. november 2022 ob 20:19:53 CET je Samuel Holland napisal(a): > When communicating with a PMIC during system poweroff (pm_power_off()), > IRQs are disabled and we are in a RCU read-side critical section, so we > cannot use wait_for_completion_io_timeout(). Instead, poll the status > register for transfer completion. > > Signed-off-by: Samuel Holland <samuel@sholland.org> > --- > > drivers/bus/sunxi-rsb.c | 23 +++++++++++++++++------ > 1 file changed, 17 insertions(+), 6 deletions(-) > > diff --git a/drivers/bus/sunxi-rsb.c b/drivers/bus/sunxi-rsb.c > index 17343cd75338..0f0e498d4379 100644 > --- a/drivers/bus/sunxi-rsb.c > +++ b/drivers/bus/sunxi-rsb.c > @@ -267,6 +267,9 @@ EXPORT_SYMBOL_GPL(sunxi_rsb_driver_register); > /* common code that starts a transfer */ > static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb) > { > + bool timeout; > + u32 status; > + > if (readl(rsb->regs + RSB_CTRL) & RSB_CTRL_START_TRANS) { > dev_dbg(rsb->dev, "RSB transfer still in progress\n"); > return -EBUSY; > @@ -279,8 +282,16 @@ static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb) > writel(RSB_CTRL_START_TRANS | RSB_CTRL_GLOBAL_INT_ENB, > rsb->regs + RSB_CTRL); > > - if (!wait_for_completion_io_timeout(&rsb->complete, > - msecs_to_jiffies(100))) { > + if (irqs_disabled()) { > + timeout = readl_poll_timeout_atomic(rsb->regs + RSB_INTS, > + status, status, 10, 100000); It would be good to check only for RSB_INTS_LOAD_BSY, RSB_INTS_TRANS_ERR and RSB_INTS_TRANS_OVER flags and clear them afterwards. That way we avoid problems if this path is used outside power off case. Best regards, Jernej > + } else { > + timeout = !wait_for_completion_io_timeout(&rsb- >complete, > + msecs_to_jiffies(100)); > + status = rsb->status; > + } > + > + if (timeout) { > dev_dbg(rsb->dev, "RSB timeout\n"); > > /* abort the transfer */ > @@ -292,18 +303,18 @@ static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb) > return -ETIMEDOUT; > } > > - if (rsb->status & RSB_INTS_LOAD_BSY) { > + if (status & RSB_INTS_LOAD_BSY) { > dev_dbg(rsb->dev, "RSB busy\n"); > return -EBUSY; > } > > - if (rsb->status & RSB_INTS_TRANS_ERR) { > - if (rsb->status & RSB_INTS_TRANS_ERR_ACK) { > + if (status & RSB_INTS_TRANS_ERR) { > + if (status & RSB_INTS_TRANS_ERR_ACK) { > dev_dbg(rsb->dev, "RSB slave nack\n"); > return -EINVAL; > } > > - if (rsb->status & RSB_INTS_TRANS_ERR_DATA) { > + if (status & RSB_INTS_TRANS_ERR_DATA) { > dev_dbg(rsb->dev, "RSB transfer data error\n"); > return -EIO; > }
Dne sobota, 05. november 2022 ob 20:46:47 CET je Jernej Škrabec napisal(a): > Dne sobota, 05. november 2022 ob 20:19:53 CET je Samuel Holland napisal(a): > > When communicating with a PMIC during system poweroff (pm_power_off()), > > IRQs are disabled and we are in a RCU read-side critical section, so we > > cannot use wait_for_completion_io_timeout(). Instead, poll the status > > register for transfer completion. > > > > Signed-off-by: Samuel Holland <samuel@sholland.org> Also a fixes tag would be in order here. Best regards, Jernej > > --- > > > > drivers/bus/sunxi-rsb.c | 23 +++++++++++++++++------ > > 1 file changed, 17 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/bus/sunxi-rsb.c b/drivers/bus/sunxi-rsb.c > > index 17343cd75338..0f0e498d4379 100644 > > --- a/drivers/bus/sunxi-rsb.c > > +++ b/drivers/bus/sunxi-rsb.c > > @@ -267,6 +267,9 @@ EXPORT_SYMBOL_GPL(sunxi_rsb_driver_register); > > > > /* common code that starts a transfer */ > > static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb) > > { > > > > + bool timeout; > > + u32 status; > > + > > > > if (readl(rsb->regs + RSB_CTRL) & RSB_CTRL_START_TRANS) { > > > > dev_dbg(rsb->dev, "RSB transfer still in progress\n"); > > return -EBUSY; > > > > @@ -279,8 +282,16 @@ static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb) > > > > writel(RSB_CTRL_START_TRANS | RSB_CTRL_GLOBAL_INT_ENB, > > > > rsb->regs + RSB_CTRL); > > > > - if (!wait_for_completion_io_timeout(&rsb->complete, > > - > > msecs_to_jiffies(100))) { > > > + if (irqs_disabled()) { > > + timeout = readl_poll_timeout_atomic(rsb->regs + > > RSB_INTS, > > > + status, > > status, 10, 100000); > > It would be good to check only for RSB_INTS_LOAD_BSY, RSB_INTS_TRANS_ERR and > RSB_INTS_TRANS_OVER flags and clear them afterwards. That way we avoid > problems if this path is used outside power off case. > > Best regards, > Jernej > > > + } else { > > + timeout = !wait_for_completion_io_timeout(&rsb- > > > >complete, > > > > + > > msecs_to_jiffies(100)); > > > + status = rsb->status; > > + } > > + > > + if (timeout) { > > > > dev_dbg(rsb->dev, "RSB timeout\n"); > > > > /* abort the transfer */ > > > > @@ -292,18 +303,18 @@ static int _sunxi_rsb_run_xfer(struct sunxi_rsb > > *rsb) > > > > return -ETIMEDOUT; > > > > } > > > > - if (rsb->status & RSB_INTS_LOAD_BSY) { > > + if (status & RSB_INTS_LOAD_BSY) { > > > > dev_dbg(rsb->dev, "RSB busy\n"); > > return -EBUSY; > > > > } > > > > - if (rsb->status & RSB_INTS_TRANS_ERR) { > > - if (rsb->status & RSB_INTS_TRANS_ERR_ACK) { > > + if (status & RSB_INTS_TRANS_ERR) { > > + if (status & RSB_INTS_TRANS_ERR_ACK) { > > > > dev_dbg(rsb->dev, "RSB slave nack\n"); > > return -EINVAL; > > > > } > > > > - if (rsb->status & RSB_INTS_TRANS_ERR_DATA) { > > + if (status & RSB_INTS_TRANS_ERR_DATA) { > > > > dev_dbg(rsb->dev, "RSB transfer data > > error\n"); > > > return -EIO; > > > > }
diff --git a/drivers/bus/sunxi-rsb.c b/drivers/bus/sunxi-rsb.c index 17343cd75338..0f0e498d4379 100644 --- a/drivers/bus/sunxi-rsb.c +++ b/drivers/bus/sunxi-rsb.c @@ -267,6 +267,9 @@ EXPORT_SYMBOL_GPL(sunxi_rsb_driver_register); /* common code that starts a transfer */ static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb) { + bool timeout; + u32 status; + if (readl(rsb->regs + RSB_CTRL) & RSB_CTRL_START_TRANS) { dev_dbg(rsb->dev, "RSB transfer still in progress\n"); return -EBUSY; @@ -279,8 +282,16 @@ static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb) writel(RSB_CTRL_START_TRANS | RSB_CTRL_GLOBAL_INT_ENB, rsb->regs + RSB_CTRL); - if (!wait_for_completion_io_timeout(&rsb->complete, - msecs_to_jiffies(100))) { + if (irqs_disabled()) { + timeout = readl_poll_timeout_atomic(rsb->regs + RSB_INTS, + status, status, 10, 100000); + } else { + timeout = !wait_for_completion_io_timeout(&rsb->complete, + msecs_to_jiffies(100)); + status = rsb->status; + } + + if (timeout) { dev_dbg(rsb->dev, "RSB timeout\n"); /* abort the transfer */ @@ -292,18 +303,18 @@ static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb) return -ETIMEDOUT; } - if (rsb->status & RSB_INTS_LOAD_BSY) { + if (status & RSB_INTS_LOAD_BSY) { dev_dbg(rsb->dev, "RSB busy\n"); return -EBUSY; } - if (rsb->status & RSB_INTS_TRANS_ERR) { - if (rsb->status & RSB_INTS_TRANS_ERR_ACK) { + if (status & RSB_INTS_TRANS_ERR) { + if (status & RSB_INTS_TRANS_ERR_ACK) { dev_dbg(rsb->dev, "RSB slave nack\n"); return -EINVAL; } - if (rsb->status & RSB_INTS_TRANS_ERR_DATA) { + if (status & RSB_INTS_TRANS_ERR_DATA) { dev_dbg(rsb->dev, "RSB transfer data error\n"); return -EIO; }
When communicating with a PMIC during system poweroff (pm_power_off()), IRQs are disabled and we are in a RCU read-side critical section, so we cannot use wait_for_completion_io_timeout(). Instead, poll the status register for transfer completion. Signed-off-by: Samuel Holland <samuel@sholland.org> --- drivers/bus/sunxi-rsb.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-)