diff options
| author | Samuel Holland <samuel@sholland.org> | 2022-11-14 04:57:48 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-08 13:16:29 +0300 |
| commit | 6d8664d4590cb6e06f0100bb3def9a1dc289fd36 (patch) | |
| tree | d51ed22d5c223d7273985a3b0a63b25b6a42f41f | |
| parent | 98a2e5387b64c3eb1183cdc1b4525abc3aec6768 (diff) | |
| download | linux-6d8664d4590cb6e06f0100bb3def9a1dc289fd36.tar.xz | |
bus: sunxi-rsb: Support atomic transfers
[ Upstream commit 077686da0e2162c4ea5ae0df205849c2a7a84479 ]
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.
Fixes: d787dcdb9c8f ("bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20221114015749.28490-3-samuel@sholland.org
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/bus/sunxi-rsb.c | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/drivers/bus/sunxi-rsb.c b/drivers/bus/sunxi-rsb.c index b85d013a9185..d3fb350dc9ee 100644 --- a/drivers/bus/sunxi-rsb.c +++ b/drivers/bus/sunxi-rsb.c @@ -268,6 +268,9 @@ EXPORT_SYMBOL_GPL(sunxi_rsb_driver_register); /* common code that starts a transfer */ static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb) { + u32 int_mask, status; + bool timeout; + if (readl(rsb->regs + RSB_CTRL) & RSB_CTRL_START_TRANS) { dev_dbg(rsb->dev, "RSB transfer still in progress\n"); return -EBUSY; @@ -275,13 +278,23 @@ static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb) reinit_completion(&rsb->complete); - writel(RSB_INTS_LOAD_BSY | RSB_INTS_TRANS_ERR | RSB_INTS_TRANS_OVER, - rsb->regs + RSB_INTE); + int_mask = RSB_INTS_LOAD_BSY | RSB_INTS_TRANS_ERR | RSB_INTS_TRANS_OVER; + writel(int_mask, rsb->regs + RSB_INTE); 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 & int_mask), + 10, 100000); + writel(status, rsb->regs + RSB_INTS); + } 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 */ @@ -293,18 +306,18 @@ 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; } |