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authorLinus Torvalds <torvalds@linux-foundation.org>2019-11-17 08:15:41 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-11-17 08:15:41 -0800
commit6b27354cca8e9d9ab7c5bfb8a34101d52b5e48c4 (patch)
treed4e334035b57b4dbd8bb32dc9d2c637652832307
parent1d4c79ed324ad780cfc3ad38364ba1fd585dd2a8 (diff)
parenta4c2fec16f5e6a5fee4865e6e0e91e2bc2d10f37 (diff)
downloadlinux-sh-6b27354cca8e9d9ab7c5bfb8a34101d52b5e48c4.tar.gz
Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang: "An I2C core fix to prevent a use-after-free in a rare error path, and an I2C ACPI addition to work around broken HW/firmware related to touchscreens" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: core: fix use after free in of_i2c_notify i2c: acpi: Force bus speed to 400KHz if a Silead touchscreen is present
-rw-r--r--drivers/i2c/i2c-core-acpi.c28
-rw-r--r--drivers/i2c/i2c-core-of.c4
2 files changed, 29 insertions, 3 deletions
diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 9cb2aa1e20ef..62a1c92ab803 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -39,6 +39,7 @@ struct i2c_acpi_lookup {
int index;
u32 speed;
u32 min_speed;
+ u32 force_speed;
};
/**
@@ -285,6 +286,19 @@ i2c_acpi_match_device(const struct acpi_device_id *matches,
return acpi_match_device(matches, &client->dev);
}
+static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
+ /*
+ * These Silead touchscreen controllers only work at 400KHz, for
+ * some reason they do not work at 100KHz. On some devices the ACPI
+ * tables list another device at their bus as only being capable
+ * of 100KHz, testing has shown that these other devices work fine
+ * at 400KHz (as can be expected of any recent i2c hw) so we force
+ * the speed of the bus to 400 KHz if a Silead device is present.
+ */
+ { "MSSL1680", 0 },
+ {}
+};
+
static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
void *data, void **return_value)
{
@@ -303,6 +317,9 @@ static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
if (lookup->speed <= lookup->min_speed)
lookup->min_speed = lookup->speed;
+ if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
+ lookup->force_speed = 400000;
+
return AE_OK;
}
@@ -340,7 +357,16 @@ u32 i2c_acpi_find_bus_speed(struct device *dev)
return 0;
}
- return lookup.min_speed != UINT_MAX ? lookup.min_speed : 0;
+ if (lookup.force_speed) {
+ if (lookup.force_speed != lookup.min_speed)
+ dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",
+ lookup.min_speed, lookup.force_speed);
+ return lookup.force_speed;
+ } else if (lookup.min_speed != UINT_MAX) {
+ return lookup.min_speed;
+ } else {
+ return 0;
+ }
}
EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
index 6f632d543fcc..7eb41990bd6d 100644
--- a/drivers/i2c/i2c-core-of.c
+++ b/drivers/i2c/i2c-core-of.c
@@ -245,14 +245,14 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
}
client = of_i2c_register_device(adap, rd->dn);
- put_device(&adap->dev);
-
if (IS_ERR(client)) {
dev_err(&adap->dev, "failed to create client for '%pOF'\n",
rd->dn);
+ put_device(&adap->dev);
of_node_clear_flag(rd->dn, OF_POPULATED);
return notifier_from_errno(PTR_ERR(client));
}
+ put_device(&adap->dev);
break;
case OF_RECONFIG_CHANGE_REMOVE:
/* already depopulated? */