On Fri, Aug 08, 2025 at 11:52:59AM +0200, Henrik Grimler wrote: > Hi Dmitry, > > On Sun, Jul 27, 2025 at 08:07:37PM +0300, Dmitry Baryshkov wrote: > > On Thu, Jul 24, 2025 at 08:50:53PM +0200, Henrik Grimler wrote: > > > To use MHL we currently need the MHL chip to be permanently on, which > > > consumes unnecessary power. Let's use extcon attached to MUIC to enable > > > the MHL chip only if it detects an MHL cable. > > > > Does HPD GPIO reflect the correct state of the cable? > > Yes, the HPD gpio pin changes state from low to high when a mhl cable is > connected: > > $ sudo cat /sys/kernel/debug/gpio|grep gpio-755 > gpio-755 ( |hpd ) in lo IRQ > $ sudo cat /sys/kernel/debug/gpio|grep gpio-755 > gpio-755 ( |hpd ) in hi IRQ > > so that is described correctly. >
Ack. > > and in captured trace I see that on cable connect we get an irq that > is handled through: > 1. max77693_muic_irq_handler > 2. max77693_muic_irq_work > 3. max77693_muic_adc_handler > 4. sii9234_extcon_notifier > 5. sii9234_extcon_work > 6. sii9234_cable_in > 7. hdmi_irq_thread > > Raw captured trace dat file can be found here: > https://grimler.se/files/sii9234-mhl-connect-trace.dat > > Maybe you were asking for some other type of order of events log > though, please let me know if I misunderstand. > > > Should the sii9234 signal to Exynos HDMI that the link is established? > > Maybe.. Sorry, I do not know enough about extcon and drm yet. I assume > you mean through drm_helper_hpd_irq_event() and > drm_bridge_hpd_notify(), I will experiment a bit and add it to the > driver and see if this improves it. If you are getting the HDMI IRQ event, then I'd suggest checking that you are actually getting the 'plugged' event, etc. I was worried that you are hijacking the DRM chain. But if you are getting hotplug events, then it's fine (and most likely correct). > > There is currently (as I wrote to Marek Szyprowski in a response in > v1) an issue where device screen stops working if cable is connected > when device screen is off, maybe proper notification would help.. > > > > Signed-off-by: Henrik Grimler <hen...@grimler.se> > > > --- > > > v2: add dependency on extcon. Issue reported by kernel test robot > > > <l...@intel.com> > > > --- > > > drivers/gpu/drm/bridge/Kconfig | 1 + > > > drivers/gpu/drm/bridge/sii9234.c | 89 > > > ++++++++++++++++++++++++++++++++++++++-- > > > 2 files changed, 87 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/bridge/Kconfig > > > b/drivers/gpu/drm/bridge/Kconfig > > > index > > > b9e0ca85226a603a24f90c6879d1499f824060cb..f18a083f6e1c6fe40bde5e65a1548acc61a162ae > > > 100644 > > > --- a/drivers/gpu/drm/bridge/Kconfig > > > +++ b/drivers/gpu/drm/bridge/Kconfig > > > @@ -303,6 +303,7 @@ config DRM_SII902X > > > config DRM_SII9234 > > > tristate "Silicon Image SII9234 HDMI/MHL bridge" > > > depends on OF > > > + select EXTCON > > > > Either this or 'depends on EXTCON || !EXTCON' > > Feels like depends is a better description so will change to it, > thanks! > > Best regards, > Henrik Grimler > > > > help > > > Say Y here if you want support for the MHL interface. > > > It is an I2C driver, that detects connection of MHL bridge > > > > -- > > With best wishes > > Dmitry > > -- With best wishes Dmitry
