Hi Dmitry, On Mon, Aug 18, 2025 at 03:42:07AM +0300, Dmitry Baryshkov wrote: > 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). With some debugging in sii9234_extcon_notifier added: --- a/drivers/gpu/drm/bridge/sii9234.c +++ b/drivers/gpu/drm/bridge/sii9234.c @@ -892,6 +892,8 @@ static int sii9234_extcon_notifier(struct notifier_block *self, struct sii9234 *ctx = container_of(self, struct sii9234, extcon_nb); + dev_info(ctx->dev, "extcon event %lu\n", event); + schedule_work(&ctx->extcon_wq); return NOTIFY_DONE; I see that sii9234 receives the hotplug event. On plug in: [ 532.132981] sii9234 15-0039: extcon event 0 [ 532.136601] max77693-muic max77693-muic: external connector is attached (adc:0x00, prev_adc:0x0) [ 532.142777] sii9234 15-0039: RSEN_HIGH without RGND_1K [ 532.149815] sii9234 15-0039: extcon event 1 [ 532.155662] max77693-charger max77693-charger: not charging. connector type: 13 [ 532.164801] sii9234 15-0039: extcon event 0 [ 532.168371] max77693-muic max77693-muic: external connector is detached(chg_type:0x0, prev_chg_type:0x0) [ 532.178370] sii9234 15-0039: extcon event 0 [ 532.188250] max77693-charger max77693-charger: not charging. connector type: 13 [ 533.097415] i2c i2c-15: sendbytes: NAK bailout. [ 533.100735] sii9234 15-0039: writebm: TPI[0x3d] <- 0x3e [ 533.115161] sii9234 15-0039: writeb: TPI[0x3d] <- 0x00 and disconnect: [ 547.195219] dwc2 12480000.usb: new device is full-speed [ 547.204912] max77693-muic max77693-muic: external connector is attached (adc:0x00, prev_adc:0x0) [ 547.212629] sii9234 15-0039: extcon event 1 [ 547.218304] max77693-charger max77693-charger: not charging. connector type: 13 [ 548.159257] i2c i2c-15: sendbytes: NAK bailout. [ 548.162602] sii9234 15-0039: writebm: TPI[0x3d] <- 0x3e [ 548.167990] sii9234 15-0039: extcon event 0 [ 548.172788] max77693-muic max77693-muic: external connector is attached (adc:0x00, prev_adc:0x0) [ 548.181336] sii9234 15-0039: extcon event 1 [ 548.186510] max77693-charger max77693-charger: not charging. connector type: 13 It seems a bit weird to me that it receives multiple events, but maybe that is expected. Will send a v3 shortly, thank you! Best regards, Henrik Grimler
