Hi, On Thu, Nov 07, 2013 at 12:10:41PM -0600, Bin Liu wrote: > On Thu, Nov 7, 2013 at 12:01 PM, Felipe Balbi <balbi@xxxxxx> wrote: > > Hi, > > > > On Thu, Nov 07, 2013 at 11:54:48AM -0600, Bin Liu wrote: > >> I am debugging a weird musb problem in which musb is in high-speed > >> device mode loaded with g_mass_storage. For some reason, musb received > >> 10 bytes in SETUP packets during enumeration. Please see the following > >> log from musb. > >> > >> <after connected to host> > >> [ 447.100858] musb-hdrc musb-hdrc.0: usbintr (1) epintr(0) > >> [ 447.250856] musb-hdrc musb-hdrc.0: usbintr (4) epintr(0) > >> [ 447.569139] musb-hdrc musb-hdrc.0: usbintr (0) epintr(1) > >> [ 447.574515] musb_g_ep0_irq 720: SetupEnd came in a wrong ep0stage setup > >> [ 447.581189] musb_g_ep0_irq 815: SETUP packet len 10 != 8 ? > >> [ 447.586737] musb-hdrc musb-hdrc.0: usbintr (0) epintr(1) > >> [ 447.592103] musb_g_ep0_irq 815: SETUP packet len 10 != 8 ? > >> [ 447.597652] musb-hdrc musb-hdrc.0: Unhandled USB IRQ 00000001-00000000 > >> ...... > >> > >> When look at the following code in musb_gadget_ep0.c, when len != 8, > >> musb_read_setup() is not called, so it just breaks out without > >> flushing the fifo or sending > >> MUSB_CSR0_P_SVDRXPKTRDY. Is this a bug? I would think in this error > > > > in a sense, yes. OTOH, a setup packet with less than 8 bytes is a much > > larger bug on the host side, right ? Still, I think that you should > > reply with a stall in that case. > > I am in the early stage of the investigation, there are still many > things I need to check, but I am guessing the 10-byte SETUP issue is > due to signal integrity. The device chip (musb) and the host chip are > on the same board, DP/DM are directly wired together (that is why I > cannot hook up an analyzer yet). > > I just came across to this portion of the code, and was wondering this > is a bug in the driver which does not handle this corner case > properly. Thanks for the confirmation. note also that ep0 handling in MUSB is less than ideal. The SW state machine implemented there doesn't take care of all cases properly. See that SetupEnd came in wrong ep0stage ? That's enough to reply with a Stall. cheers -- balbi
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