Thinh Nguyen wrote: > From: Yu Chen <chenyu56@xxxxxxxxxx> > From: John Stultz <john.stultz@xxxxxxxxxx> > > According to the programming guide, to switch mode for DRD controller, > the driver needs to do the following. > > To switch from device to host: > 1. Reset controller with GCTL.CoreSoftReset > 2. Set GCTL.PrtCapDir(host mode) > 3. Reset the host with USBCMD.HCRESET > 4. Then follow up with the initializing host registers sequence > > To switch from host to device: > 1. Reset controller with GCTL.CoreSoftReset > 2. Set GCTL.PrtCapDir(device mode) > 3. Reset the device with DCTL.CSftRst > 4. Then follow up with the initializing registers sequence > > Currently we're missing step 1) to do GCTL.CoreSoftReset and step 3) of > switching from host to device. John Stult reported a lockup issue seen > with HiKey960 platform without these steps[1]. Similar issue is observed > with Ferry's testing platform[2]. > > So, apply the required steps along with some fixes to Yu Chen's and John > Stultz's version. The main fixes to their versions are the missing wait > for clocks synchronization before clearing GCTL.CoreSoftReset and only > apply DCTL.CSftRst when switching from host to device. > > [1] https://urldefense.com/v3/__https://lore.kernel.org/linux-usb/20210108015115.27920-1-john.stultz@xxxxxxxxxx/__;!!A4F2R9G_pg!PW9Jbs4wv4a_zKGgZHN0FYrIpfecPX0Ouq9V3d16Yz-9-GSHqZWsfBAF-WkeqLhzN4i3$ > [2] https://urldefense.com/v3/__https://lore.kernel.org/linux-usb/0ba7a6ba-e6a7-9cd4-0695-64fc927e01f1@xxxxxxxxx/__;!!A4F2R9G_pg!PW9Jbs4wv4a_zKGgZHN0FYrIpfecPX0Ouq9V3d16Yz-9-GSHqZWsfBAF-WkeqGeZStt4$ > > Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > Cc: Ferry Toth <fntoth@xxxxxxxxx> > Cc: Wesley Cheng <wcheng@xxxxxxxxxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> > Fixes: 41ce1456e1db ("usb: dwc3: core: make dwc3_set_mode() work properly") > Signed-off-by: Yu Chen <chenyu56@xxxxxxxxxx> > Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx> > Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> > --- > Changes in v3: > - Check if the desired mode is OTG, then keep the old flow > - Remove condition for OTG support only since the device can still be > configured DRD host/device mode only > - Remove redundant hw_mode check since __dwc3_set_mode() only applies when > hw_mode is DRD > Changes in v2: > - Initialize mutex per device and not as global mutex. > - Add additional checks for DRD only mode > > drivers/usb/dwc3/core.c | 27 +++++++++++++++++++++++++++ > drivers/usb/dwc3/core.h | 5 +++++ > 2 files changed, 32 insertions(+) > Hi John, If possible, can you run a test with this version on your platform? Thanks, Thinh
