Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
+29
-3
+27
-1
drivers/i2c/i2c-core-acpi.c
+27
-1
drivers/i2c/i2c-core-acpi.c
···
39
39
int index;
40
40
u32 speed;
41
41
u32 min_speed;
42
+
u32 force_speed;
42
43
};
43
44
44
45
/**
···
286
285
return acpi_match_device(matches, &client->dev);
287
286
}
288
287
288
+
static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
289
+
/*
290
+
* These Silead touchscreen controllers only work at 400KHz, for
291
+
* some reason they do not work at 100KHz. On some devices the ACPI
292
+
* tables list another device at their bus as only being capable
293
+
* of 100KHz, testing has shown that these other devices work fine
294
+
* at 400KHz (as can be expected of any recent i2c hw) so we force
295
+
* the speed of the bus to 400 KHz if a Silead device is present.
296
+
*/
297
+
{ "MSSL1680", 0 },
298
+
{}
299
+
};
300
+
289
301
static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
290
302
void *data, void **return_value)
291
303
{
···
316
302
317
303
if (lookup->speed <= lookup->min_speed)
318
304
lookup->min_speed = lookup->speed;
305
+
306
+
if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
307
+
lookup->force_speed = 400000;
319
308
320
309
return AE_OK;
321
310
}
···
357
340
return 0;
358
341
}
359
342
360
-
return lookup.min_speed != UINT_MAX ? lookup.min_speed : 0;
343
+
if (lookup.force_speed) {
344
+
if (lookup.force_speed != lookup.min_speed)
345
+
dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",
346
+
lookup.min_speed, lookup.force_speed);
347
+
return lookup.force_speed;
348
+
} else if (lookup.min_speed != UINT_MAX) {
349
+
return lookup.min_speed;
350
+
} else {
351
+
return 0;
352
+
}
361
353
}
362
354
EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
363
355
+2
-2
drivers/i2c/i2c-core-of.c
+2
-2
drivers/i2c/i2c-core-of.c
···
245
245
}
246
246
247
247
client = of_i2c_register_device(adap, rd->dn);
248
-
put_device(&adap->dev);
249
-
250
248
if (IS_ERR(client)) {
251
249
dev_err(&adap->dev, "failed to create client for '%pOF'\n",
252
250
rd->dn);
251
+
put_device(&adap->dev);
253
252
of_node_clear_flag(rd->dn, OF_POPULATED);
254
253
return notifier_from_errno(PTR_ERR(client));
255
254
}
255
+
put_device(&adap->dev);
256
256
break;
257
257
case OF_RECONFIG_CHANGE_REMOVE:
258
258
/* already depopulated? */