2020-01-14 15:12:30

by Charles Keepax

Subject: [PATCH RESEND 2/3] mfd: madera: Wait for boot done before accessing any other registers

It is advised to wait for the boot done bit to be set before reading
any other register, update the driver to respect this.

Signed-off-by: Charles Keepax <[email protected]>
---

This patch can be applied separately from the other patches in the series,
if needed. Just resending to keep everything together in one chain.

Thanks,
Charles

drivers/mfd/madera-core.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/mfd/madera-core.c b/drivers/mfd/madera-core.c
index a8cfadc1fc01e..a7d50a7fa625d 100644
--- a/drivers/mfd/madera-core.c
+++ b/drivers/mfd/madera-core.c
@@ -199,7 +199,7 @@ EXPORT_SYMBOL_GPL(madera_name_from_type);
#define MADERA_BOOT_POLL_INTERVAL_USEC 5000
#define MADERA_BOOT_POLL_TIMEOUT_USEC 25000

-static int madera_wait_for_boot(struct madera *madera)
+static int madera_wait_for_boot_noack(struct madera *madera)
{
ktime_t timeout;
unsigned int val = 0;
@@ -226,6 +226,13 @@ static int madera_wait_for_boot(struct madera *madera)
ret = -ETIMEDOUT;
}

+ return ret;
+}
+
+static int madera_wait_for_boot(struct madera *madera)
+{
+ int ret = madera_wait_for_boot_noack(madera);
+
/*
* BOOT_DONE defaults to unmasked on boot so we must ack it.
* Do this even after a timeout to avoid interrupt storms.
@@ -545,6 +552,12 @@ int madera_dev_init(struct madera *madera)
regcache_cache_only(madera->regmap, false);
regcache_cache_only(madera->regmap_32bit, false);

+ ret = madera_wait_for_boot_noack(madera);
+ if (ret) {
+ dev_err(madera->dev, "Device failed initial boot: %d\n", ret);
+ goto err_reset;
+ }
+
/*
* Now we can power up and verify that this is a chip we know about
* before we start doing any writes to its registers.
@@ -650,7 +663,7 @@ int madera_dev_init(struct madera *madera)

ret = madera_wait_for_boot(madera);
if (ret) {
- dev_err(madera->dev, "Device failed initial boot: %d\n", ret);
+ dev_err(madera->dev, "Failed to clear boot done: %d\n", ret);
goto err_reset;
}

--
2.11.0

2020-01-16 13:24:32

by Lee Jones

Subject: Re: [PATCH RESEND 2/3] mfd: madera: Wait for boot done before accessing any other registers

On Tue, 14 Jan 2020, Charles Keepax wrote:

> It is advised to wait for the boot done bit to be set before reading
> any other register, update the driver to respect this.
>
> Signed-off-by: Charles Keepax <[email protected]>
> ---
>
> This patch can be applied separately from the other patches in the series,
> if needed. Just resending to keep everything together in one chain.
>
> Thanks,
> Charles
>
> drivers/mfd/madera-core.c | 17 +++++++++++++++--
> 1 file changed, 15 insertions(+), 2 deletions(-)

Just applied v1 of this.

--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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