Hello, On 02/08/2016 07:54 AM, Wolfram Sang wrote:
On Wed, Feb 03, 2016 at 10:46:51AM -0300, Javier Martinez Canillas wrote:Hello Wolfram, I've a issue with a I2C video decoder driver (drivers/media/i2c/tvp5150.c). In v4.5-rc1, the driver gets I2C read / writes timeouts when accessing the device I2C registers: tvp5150 1-005c: i2c i/o error: rc == -110 tvp5150: probe of 1-005c failed with error -110 The driver used to work up to v4.4 so this is a regression in v4.5-rc1: tvp5150 1-005c: tvp5151 (1.0) chip found @ 0xb8 (OMAP I2C adapter) tvp5150 1-005c: tvp5151 detected. I tracked down to commit 9f924169c035 ("i2c: always enable RuntimePM for the adapter device") and reverting that commit makes things to work again. The tvp5150 driver doesn't have runtime PM support but the I2C controller driver does (drivers/i2c/busses/i2c-omap.c) FWIW. I tried adding runtime PM support to tvp5150 (basically calling pm_runtime enable/get on probe before the first I2C read to resume the controller) but that it did not work. Not filling the OMAP I2C driver's runtime PM callbacks does not help either. Any hints about the proper way to fix this issue?Asking linux-pm for help: The commit in question enables RuntimePM for the logical adapter device which sits between the HW I2C controller and the I2C client device. This adapter device has been used with pm_runtime_no_callbacks before enabling RPM. Now, Alan explained to me that "suspend events will propagate from the I2C clients all the way up to the adapter's parent." with RPM enabled for the adapter device. Which should be a no-op if the client doesn't do any PM at all? What do I miss? Thanks, Wolfram
I'm adding Tony Lindgren to the cc list as well since he is the OMAP maintainer and I see that has struggled lately with runtime PM issues so maybe he has more ideas. Best regards, -- Javier Martinez Canillas Open Source Group Samsung Research America -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
