From mboxrd@z Thu Jan 1 00:00:00 1970 From: b-liu@ti.com (Bin Liu) Date: Tue, 8 Dec 2015 08:42:47 -0600 Subject: [PATCH] usb: musb: dsps: handle the otg_state_a_wait_vrise_timeout case In-Reply-To: <87egexm2jr.fsf@saruman.tx.rr.com> References: <1440087153-31084-1-git-send-email-gregory.clement@free-electrons.com> <55D719B1.8010700@free-electrons.com> <87twrfsbed.fsf@free-electrons.com> <87d1wtf5ir.fsf@saruman.tx.rr.com> <87a8rde96m.fsf@free-electrons.com> <87poyiegc7.fsf@free-electrons.com> <87poyinjpc.fsf@saruman.tx.rr.com> <874mft9ukx.fsf@free-electrons.com> <87h9jtm37m.fsf@saruman.tx.rr.com> <5666E9BE.5070907@ti.com> <87egexm2jr.fsf@saruman.tx.rr.com> Message-ID: <5666EC67.7000203@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 12/08/2015 08:35 AM, Felipe Balbi wrote: > > Hi, > > Bin Liu writes: >> Felipe, >> >> On 12/08/2015 08:20 AM, Felipe Balbi wrote: >>> >>> Hi, >>> >>> Gregory CLEMENT writes: >>>>>>> if it is the case then it didn't fix the issue I had. >>>>>>> >>>>>>> I activated the following debug line: >>>>>>> >>>>>>> [musb_hdrc]musb_interrupt =_ "** IRQ %s usb%04x tx%04x rx%04x\012" >>>>>>> [musb_dsps]dsps_interrupt =p "usbintr (%x) epintr(%x)\012" >>>>>>> >>>>>>> But I didn't get any interrupt while disconnecting the cable without any >>>>>>> device connected on it (whereas I got an interrupt when I connected it). >>>>>>> >>>>>>> Note that I applied this patch instead of the "usb: musb: dsps: handle >>>>>>> the otg_state_a_wait_vrise_timeout case", is what you had in mind ? >>>>> >>>>> yeah, that's what I had in mind. But your patch seems wrong :-) >>>>> >>>>> I tried writing a more correct version here and found 2 issues: >>>>> >>>>> a) bit 3 doesn't do anything :-p I cannot read IRQs from mentor's >>>>> registers >>>>> >>>>> b) when setting RESET_ISOLATION bit, reads of CTRL register hang. Note >>>>> that according to TRM, RESET_ISOLATION _must_ be set prior to a soft >>>>> reset and cleared afterwards. But right after setting RESET_ISOLATION, >>>>> if I try a read of CTRL, it'll hang forever. >>>> >>>> The datasheet seems not very coherent about it, >>>> >>>> on one side we have: >>>> "This bit should be set high prior to setting bit 0 and cleared after bit 0 >>>> is cleared." >>>> >>>> and on the other side: >>>> "Both the soft_reset and soft_reset_isolation bits should be asserted >>>> simultaneously." >>>> >>>> The hang you saw could be explained by the following: >>>> "Setting only the soft_reset_isolation bit will cause all USB0 output >>>> signals to go to a known constant value via multiplexers. >>>> This will >>>> prevent future access to USB0." page 2567 >>> >>> good catch. Setting them together makes the hang go away. >>> >>> I still have the other problem, which is legacy IRQ reporting mode not >>> really working. >>> >> >> I never tried to change the IRQ mapping. The 8 MUSB interrupt will be >> the same no matter where they are reported from. What do you expect when >> switch to the MUSB IRQ reporting mode? > > read events from MUSB's registers instead of TI's :-) so, MUSB_INTRUSB, > MUSB_INTRRX and MUSB_INTRTX. > I meant you expect to see any different event when switch to MUSB IRQ mode? The TI wrapper just reports the same 8 interrupt events. I don't think you would get any difference. BTY, I think I miss some context here. This Gregory's patch is trying to fix the OTG state machine problem in musb_dsps, which is replicated with a cable without a device connected. But it also mentions about non-compliant MSC devices. How are the thumb drives related to this OTG state issue? -- Regards, -Bin.