The Lenovo Miix2 8 DSDT contains an i2c clk / bus speed of 1700000 Hz
for one if its devices, which is not supported.
This is the second DSDT to show up with an unsupported clk in a short
time, remove the hardcoded fix for DSDTs with a 1 MiHz clock and simply
always round down the clk to the nearest supported value.
Reported-by: russianneuromancer@xxxxx
Fixes: 682c6c2188 ("i2c: designware: Some broken DSTDs use 1MiHz ...")
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-designware-platdrv.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 57248bccadbc..2b98a173136f 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -256,7 +256,8 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
struct dw_i2c_dev *dev;
u32 acpi_speed, ht = 0;
struct resource *mem;
- int irq, ret;
+ int i, irq, ret;
+ const int supported_speeds[] = { 0, 100000, 400000, 1000000, 3400000 };
irq = platform_get_irq(pdev, 0);
if (irq < 0)
@@ -297,9 +298,16 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
}
acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
- /* Some broken DSTDs use 1MiHz instead of 1MHz */
- if (acpi_speed == 1048576)
- acpi_speed = 1000000;
+ /*
+ * Some DSTDs use a non standard speed, round down to the lowest
+ * standard speed.
+ */
+ for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) {
+ if (acpi_speed < supported_speeds[i])
+ break;
+ }
+ acpi_speed = supported_speeds[i - 1];
+
/*
* Find bus speed from the "clock-frequency" device property, ACPI
* or by using fast mode if neither is set.
--
2.13.4
