How download complete patch series from patchwork?

The patchwork project information page at https://patchwork.linuxtv.org/project/linux-media/ has a couple of links at the bottom to pwclient and a sample .pwclientrc

Once you set these up, you can use pwclient list to search for patches and pwclient git-am to apply them. The awkward part is that there's apparently no single command to search and apply in one go. I used a combination of the two to get (for example) Philipp Zabel's recent IPU CSI patch series like this...

pwclient list -w "Philipp Zabel" -s New v2 -f %{id} | egrep '^[0-9]' | xargs pwclient git-am

One way I can think of is to access gmane.linux.drivers.video-input-infrastructure mailing list using Gmane NNTP interface with a client and download all messages. For example, you can use a command-line client called slrn. There are also many GUI clients available. Many of them are capable of downloading multiple messages in mbox format.

In addition to Ian-Arkver's answer, if your mailing list supports at least patchwork 2.0 you can also use git-pw. Which can handle series directly (for the moment only ozlabs seems to have updated though, so I'll just make an artificial example)

git-pw --server https://patchwork.ozlabs.org --project linux-imx series apply 34215

Please take note, you'll also need to provide authentication with either their api token or your account credentials.