Felipe, On Fri, Nov 20, 2015 at 7:40 AM, Felipe Balbi <balbi@xxxxxx> wrote: > > Hi, > > Douglas Anderson <dianders@xxxxxxxxxxxx> writes: >> In general it is wise to clear interrupts before processing them. If >> you don't do that, you can get: >> 1. Interrupt happens >> 2. You look at system state and process interrupt >> 3. A new interrupt happens >> 4. You clear interrupt without processing it. >> >> This patch was actually a first attempt to fix missing device insertions >> as described in (usb: dwc2: host: Fix missing device insertions) and it >> did solve some of the signal bouncing problems but not all of >> them (which is why I submitted the other patch). Specifically, this >> patch itself would sometimes change: >> 1. hardware sees connect >> 2. hardware sees disconnect >> 3. hardware sees connect >> 4. dwc2_port_intr() - clears connect interrupt >> 5. dwc2_handle_common_intr() - calls dwc2_hcd_disconnect() >> >> ...to: >> 1. hardware sees connect >> 2. hardware sees disconnect >> 3. dwc2_port_intr() - clears connect interrupt >> 4. hardware sees connect >> 5. dwc2_handle_common_intr() - calls dwc2_hcd_disconnect() >> >> ...but with different timing then sometimes we'd still miss cable >> insertions. >> >> In any case, though this patch doesn't fix any (known) problems, it >> still seems wise as a general policy to clear interrupt before handling >> them. >> >> Note that for dwc2_handle_usb_port_intr(), instead of moving the clear >> of PRTINT to the beginning of the function we remove it completely. The >> only way to clear PRTINT is to clear the sources that set it in the >> first place. >> >> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> >> Acked-by: John Youn <johnyoun@xxxxxxxxxxxx> >> Tested-by: John Youn <johnyoun@xxxxxxxxxxxx> > > $ patch -p1 --dry-run < patch.diff > checking file drivers/usb/dwc2/core_intr.c > checking file drivers/usb/dwc2/hcd_intr.c > Hunk #4 FAILED at 365. > Hunk #5 succeeded at 388 (offset 11 lines). > 1 out of 5 hunks FAILED > > Care to rebase on top of my testing/next ? No problem. ...though when I did that, I actually found (by code inspection) a bug in the original patch, so I guess it's a good thing it didn't apply... ...and then that led me to another bug that was pre-existing. I'll send up two new patches shortly. I'll remove John's Ack and Tested tags from the patch since it contains a change. It looks like you already landed part 1 of this series (usb: dwc2: host: Fix missing device insertions) so I won't resend that. -Doug -- 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
