Felipe, > -----Original Message----- > From: Balbi, Felipe > Sent: Thursday, April 02, 2015 1:22 PM > To: Liu, Bin > Cc: linux-usb@xxxxxxxxxxxxxxx; Balbi, Felipe > Subject: Re: [PATCH v2] usb: musb: only set test mode once > > On Thu, Apr 02, 2015 at 11:44:30AM -0500, Liu, Bin wrote: > > Felipe, > > > > > -----Original Message----- > > > From: Liu, Bin > > > Sent: Tuesday, March 24, 2015 3:09 PM > > > To: linux-usb@xxxxxxxxxxxxxxx > > > Cc: Balbi, Felipe; Liu, Bin > > > Subject: [PATCH v2] usb: musb: only set test mode once > > > > > > The MUSB test mode register can only be set once, otherwise the > > > result is undefined. > > > > > > This prevents the debugfs testmode entry to set the register more > > > than once which causes test failure. > > > > > > Signed-off-by: Bin Liu <b-liu@xxxxxx> > > > > I see you have not picked up this patch yet. Can you please hold on > > it? > > > > I noticed only the USB2.0 Specs mentioned about USB reset to exit test > > mode, but not in the MUSB data manual. > > > > I am guessing running multiple 'test packet' command causing incorrect > > test packets is due to the driver loading the test packets into EP0 > > FIFO multiple times. I simply masked this then the analyzer trace > > shows the test packets are correct even after ran 'test packet' > > command multiple times. > > > > I will have to hook up a scope to measure the signal to ensure the > > DP/DM signals are still correct after run each test mode command > > multiple times for MUSB. If so, then the patch we need is to ensure > > not loading the test packet to FIFO multiple times. > > MUSB still needs to obey what USB 2.0 specification says and if it says we must > reset, then we must reset ;-) This is right. But the Specs only says the hub reset is required when *exit* test mode, it did not say a reset is required when switching between test modes. I really don't care about reset or not, it is just about board reboot, not a big deal. The only thing I want to do is prevent the *** user using the current driver loading test packets to FIFO multiple times which breaks the test. Regards, -Bin. > > -- > balbi -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
