Hi
On 6/23/20 5:51 AM, John Stultz wrote:
On the HiKey board, where CONFIG_ACPI is not set, we started
to see a graphics regression where the adv7511 HDMI bridge driver
wasn't probing. This was due to the i2c bus failing to start up.
I bisected the problem down to commit f9288fcc5c615 ("i2c:
designware: Move ACPI parts into common module") and after
looking at it a bit, I realized that change moved some
initialization into i2c_dw_acpi_adjust_bus_speed(). However,
i2c_dw_acpi_adjust_bus_speed() is only functional if CONFIG_ACPI
is set.
This patch pulls i2c_dw_acpi_adjust_bus_speed() out of the
ifdef CONFIG_ACPI conditional, and gets the board working again.
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
Cc: Wolfram Sang <wsa@xxxxxxxxxx>
Cc: linux-i2c@xxxxxxxxxxxxxxx
Fixes: f9288fcc5c615 ("i2c: designware: Move ACPI parts into common module")
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-designware-common.c | 4 ++--
drivers/i2c/busses/i2c-designware-core.h | 3 +--
2 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
index e3a8640db7da..33de185e15f2 100644
--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -286,6 +286,8 @@ int i2c_dw_acpi_configure(struct device *device)
}
EXPORT_SYMBOL_GPL(i2c_dw_acpi_configure);
+#endif /* CONFIG_ACPI */
+
I think the regression is in these lines below that were moved from
probe to i2c_dw_acpi_adjust_bus_speed() and cause that neither
"cloock-frequency" device property or I2C_MAX_FAST_MODE_FREQ affect the
bus speed when CONFIG_ACPI is not set.
+ /*
+ * Find bus speed from the "clock-frequency" device property, ACPI
+ * or by using fast mode if neither is set.
+ */
+ if (acpi_speed && t->bus_freq_hz)
+ t->bus_freq_hz = min(t->bus_freq_hz, acpi_speed);
+ else if (acpi_speed || t->bus_freq_hz)
+ t->bus_freq_hz = max(t->bus_freq_hz, acpi_speed);
+ else
+ t->bus_freq_hz = I2C_MAX_FAST_MODE_FREQ;
Andy: what you think should the i2c_dw_acpi_adjust_bus_speed() fixed to
return adjusted speed or zero if not found (also for !CONFIG_ACPI) and
move above lines back to probe? It looks more clear to me that way and
should fix the regression I think.
--
Jarkko
