In reviewing the previous patch, Thinh Nguyen pointed out that the DRD mode change sequence should be like the following when switching from host -> device according to the programming guide (for all DRD IPs): 1. Reset controller with GCTL.CoreSoftReset 2. Set GCTL.PrtCapDir(device) 3. Soft reset with DCTL.CSftRst 4. Then follow up with the initializing registers sequence
The current code does: a. Soft reset with DCTL.CSftRst on driver probe b. Reset controller with GCTL.CoreSoftReset (added in previous patch) c. Set GCTL.PrtCapDir(device) d. < missing DCTL.CSftRst > e. Then follow up with initializing registers sequence So this patch adds the DCTL.CSftRst soft reset that was currently missing from the dwc3 mode switching. Cc: Felipe Balbi <[email protected]> Cc: Tejas Joglekar <[email protected]> Cc: Yang Fei <[email protected]> Cc: YongQin Liu <[email protected]> Cc: Andrzej Pietrasiewicz <[email protected]> Cc: Thinh Nguyen <[email protected]> Cc: Jun Li <[email protected]> Cc: Mauro Carvalho Chehab <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: [email protected] Signed-off-by: John Stultz <[email protected]> --- Feedback would be appreciated. I'm a little worried I should be conditionalizing the DCTL.CSftRst on DRD mode controllers, but I'm really not sure what the right thing to do is for non-DRD mode controllers. --- drivers/usb/dwc3/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index b6a6b90eb2d5..71f8b07ecb99 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -40,6 +40,8 @@ #define DWC3_DEFAULT_AUTOSUSPEND_DELAY 5000 /* ms */ +static int dwc3_core_soft_reset(struct dwc3 *dwc); + /** * dwc3_get_dr_mode - Validates and sets dr_mode * @dwc: pointer to our context structure @@ -177,6 +179,7 @@ static void __dwc3_set_mode(struct work_struct *work) dwc3_set_prtcap(dwc, dwc->desired_dr_role); + dwc3_core_soft_reset(dwc); spin_unlock_irqrestore(&dwc->lock, flags); switch (dwc->desired_dr_role) { -- 2.17.1
