EMB-175 flight crew reported smoke in the cockpit as well as the cabin while in cruise.

Narrative

The event occurred during the flight from ZZZ-ZZZ1. The flight time was about 30 minutes and about halfway through; the First Officer and myself noticed a thin; light greyish mist/smoke coming from my window vent. At first we assumed it was nothing and maybe just condensation vapor; but when we both smelled an electrical burnt and campfire smell we immediately executed our memory items which involved the oxygen mask and the pressurization dump button. (The dump button was pushed around FL190; which eventually caused a CABIN ALT HI EICAS but the cabin only had climbed to about 10;900 feet and NO masks were deployed) After the memory items the FO read the QRC and once that was complete I handed him controls and comms and he continued to take us to ZZZ and he flew the aircraft and [requested priority handling] with ATC. I eventually completed the associated QRH. Once that was completed; the flight attendants had been trying to call us via the comm button for a few minutes and I was at a point where I could talk to them. They informed me that there was indeed smoke in the cabin for a few minutes but it was then gone after a few minutes and they couldn't find any indication of what caused it. I then hung up with them when I was convinced that there was no inflight fire as we also had NO indication to prove otherwise. I took controls back from the FO and landed the aircraft with no issues. We taxied to the end of the runway where firetrucks met us and performed a visual and heat gun inspection to make sure nothing was happening outside the aircraft out of our view. Throughout the entire flight no FARs; or SOPs; or rules were broken. We then taxied into the gate with no other issues and completed the flight.Cause: Still unknown what caused the event; so I am not able to provide any and all contributing factors.Suggestions: Still unknown what caused the event; so I am not able to provide a suggestion of how to avoid the event.