usb: dwc2: host: Clear interrupts before handling them
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@chromium.org> Signed-off-by: Felipe Balbi <balbi@ti.com>
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