Re: [PATCH 04/14] mux: mmio: Add resume support
From: Peter Rosin <hidden>
Date: 2024-01-15 22:31:17
Also in:
linux-arm-kernel, linux-gpio, linux-i2c, linux-omap, linux-pci, lkml
Hi! 2024-01-15 at 17:14, Thomas Richard wrote:
From: Théo Lebrun <theo.lebrun@bootlin.com> Implement resume support
What Andy said, and please don't omit punctuation. Try to make it a pleasure to read your patches!
quoted hunk ↗ jump to hunk
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com> Signed-off-by: Thomas Richard <thomas.richard@bootlin.com> --- drivers/mux/mmio.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+)diff --git a/drivers/mux/mmio.c b/drivers/mux/mmio.c index fd1d121a584b..ab4ef195fc0d 100644 --- a/drivers/mux/mmio.c +++ b/drivers/mux/mmio.c@@ -125,13 +125,47 @@ static int mux_mmio_probe(struct platform_device *pdev) mux_chip->ops = &mux_mmio_ops; + dev_set_drvdata(dev, mux_chip); + return devm_mux_chip_register(dev, mux_chip); } +#ifdef CONFIG_PM +static int mux_mmio_resume_noirq(struct device *dev) +{ + struct mux_chip *mux_chip = dev_get_drvdata(dev); + int global_ret = 0; + unsigned int i; + + for (i = 0; i < mux_chip->controllers; i++) { + struct mux_control *mux = &mux_chip->mux[i]; + int val = mux->cached_state;
You are not supposed to look at (or change) cached_state outside the mux core.
+ int ret; + + if (val == MUX_IDLE_AS_IS)
The cached_state can never be MUX_IDLE_AS_IS. Sure, it happens to have the same actual value as the correct MUX_CACHE_UNKNOWN, but abusing that is all kinds of wrong.
+ continue;
+
+ ret = mux_mmio_set(mux, val);
+ if (ret) {If mux_mmio_set() fails, cached_state ends up wrong as it should be set to MUX_CACHE_UNKNOWN on failure. Low-level stuff like this needs to be done by the mux core, or things becomes a maintenance hazard... So, the meat of this function belongs in the mux core since none of it looks mmio specific. It could probably be named mux_chip_resume() or something such. That makes it simple to use the correct constant, and the mux_control_set() helper makes it easy to get the handling of cached_state right. Cheers, Peter
+ dev_err(dev, "control %u: error restoring mux: %d\n", i, ret);
+ if (!global_ret)
+ global_ret = ret;
+ }
+ }
+
+ return global_ret;
+}
+#endif
+
+static const struct dev_pm_ops mux_mmio_pm_ops = {
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, mux_mmio_resume_noirq)
+};
+
static struct platform_driver mux_mmio_driver = {
.driver = {
.name = "mmio-mux",
.of_match_table = mux_mmio_dt_ids,
+ .pm = &mux_mmio_pm_ops,
},
.probe = mux_mmio_probe,
};-- linux-phy mailing list linux-phy@lists.infradead.org https://lists.infradead.org/mailman/listinfo/linux-phy