From mboxrd@z Thu Jan 1 00:00:00 1970 From: martin.blumenstingl@googlemail.com (Martin Blumenstingl) Date: Sun, 28 Aug 2016 18:25:32 +0200 Subject: USB PHY documentation In-Reply-To: References: <4cc6ec9ce62649c283fb633b26d5cffe@codethink.co.uk> <1472029412.2322.13.camel@baylibre.com> Message-ID: To: linus-amlogic@lists.infradead.org List-Id: linus-amlogic.lists.infradead.org On Sat, Aug 27, 2016 at 11:32 PM, Martin Blumenstingl wrote: > On Fri, Aug 26, 2016 at 12:55 PM, J?r?me Brunet wrote: >> I did some test on the otg controller. I had to remove the reset in the PHY >> because it was reseting both of them, so the reset intended for the 2nd PHY >> was breaking the configuration of the 1st. > I am getting the following error when 1) removing the reset and 2) > booting the mainline kernel directly (without booting the stock > Android kernel first): > [ 1.297507] dwc2 c9000000.usb-controller: dwc2_core_reset() HANG! > AHB Idle GRSTCTL=0 > [ 1.305116] dwc2 c9000000.usb-controller: Bad value for GSNPSID: 0x00000000 I added the reset back along with some code that ensures it only calls the reset once. That made the error go away on my board. Additionally I forced the first USB controller to "host" mode (which was also not working without the reset) due to the OTG problems you have mentioned. I did some basic tests with both USB controllers - everything looks good! While doing that I found out that quite a lot bits in REG_ADP_BC are readonly - one of them is REG_ADP_BC_DRV_VBUS so I removed the code which set that bit. Finally I added our signed-off-by's to the patches and improved the patch subjects and descriptions. You can find my updated tree here: [0] (or if you only care about the USB patches: [1]) PS: I will only have limited access to my S905 device in the next two weeks. Feel free to submit the patches once you think they are ready - having USB (host) support in 4.9 would be awesome! Regards, Martin [0] https://github.com/xdarklight/linux/commits/meson-gxbb-integration-4.8-20160827 [1] https://github.com/torvalds/linux/compare/0ff577bf040b312301920f8589fc9fcea84a86b8...6aebadf13dcfb631399e7717c5eec0e80d72c9a7