On 09/21/17 11:39, Jose Abreu wrote: > Hi Jernej, > > On 20-09-2017 21:01, Jernej Skrabec wrote: >> [added media mailing list due to CEC question] >> >> This patch series adds a HDMI glue driver for Allwinner H3 SoC. For now, only >> video and CEC functionality is supported. Audio needs more tweaks. >> >> Series is based on the H3 DE2 patch series available on mailing list: >> https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.infradead.org_pipermail_linux-2Darm-2Dkernel_2017-2DAugust_522697.html&d=DwIBAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=WHDsc6kcWAl4i96Vm5hJ_19IJiuxx_p_Rzo2g-uHDKw&m=coyfcQKSr2asrHcaCeWFmAP_9nkFkRK8s7Uw5bmVei4&s=JCFaMXK1MmZ3jE745_YcqZhZkaqtc6UapGfSSapcz_s&e= >> (ignore patches marked with [NOT FOR REVIEW NOW] tag) >> >> Patch 1 adds support for polling plug detection since custom PHY used here >> doesn't support HPD interrupt. >> >> Patch 2 enables overflow workaround for v1.32a. This HDMI controller exhibits >> same issues as HDMI controller used in iMX6 SoCs. >> >> Patch 3 adds CLK_SET_RATE_PARENT to hdmi clock. >> >> Patch 4 adds dt bindings documentation. >> >> Patch 5 adds actual H3 HDMI glue driver. >> >> Patch 6 and 7 add HDMI node to DT and enable it where needed. >> >> Allwinner used DW HDMI controller in a non standard way: >> - register offsets obfuscation layer, which can fortunately be turned off >> - register read lock, which has to be disabled by magic number >> - custom PHY, which have to be initialized before DW HDMI controller >> - non standard clocks >> - no HPD interrupt >> >> Because of that, I have two questions: >> - Since HPD have to be polled, is it enough just to enable poll mode? I'm >> mainly concerned about invalidating CEC address here. > > You mean you get no interrupt when HPD status changes? Hans can > answer this better but then you will need to invalidate the cec > physical address yourself because right now its invalidated in > the dw-hdmi irq handler (see dw_hdmi_irq()). That's correct. When the HPD goes low you need to call cec_notifier_phys_addr_invalidate() to invalidate the physical address. This is not terribly time sensitive, i.e. checking this once a second would be quick enough. Regards, Hans
