On 15.01.2018 18:33, Andrzej Hajda wrote:
Chip has known bug which causes I2C client state machine to frequently enter non-idle mode after chip reset. Let's ask I2C adapter to perform bus recovery to mitigate this bug.
Signed-off-by: Andrzej Hajda a.hajda@samsung.com
drivers/gpu/drm/bridge/sil-sii8620.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c b/drivers/gpu/drm/bridge/sil-sii8620.c index 86789f8918a4..db93e5e0497c 100644 --- a/drivers/gpu/drm/bridge/sil-sii8620.c +++ b/drivers/gpu/drm/bridge/sil-sii8620.c @@ -978,6 +978,8 @@ static int sii8620_hw_off(struct sii8620 *ctx)
static void sii8620_hw_reset(struct sii8620 *ctx) {
- struct i2c_client *i2c = to_i2c_client(ctx->dev);
- usleep_range(10000, 20000); gpiod_set_value(ctx->gpio_reset, 0); usleep_range(5000, 20000);
@@ -985,6 +987,9 @@ static void sii8620_hw_reset(struct sii8620 *ctx) usleep_range(10000, 20000); gpiod_set_value(ctx->gpio_reset, 0); msleep(300);
- /* I2C bus recovery prevents I2C errors due to known bug in the chip */
- i2c_recover_bus(i2c->adapter);
}
static void sii8620_cbus_reset(struct sii8620 *ctx)
I have just posted patch which deals with the problem directly in i2c adapter, so this patch can be dropped[1].
[1]: https://marc.info/?l=linux-i2c&m=151696860906805
Regards
Andrzej