lsp-mode open declaration / definition in other window

I'm starting to feel a bit frustrated: this should be as simple as setting some variable or other, but I'm unable to find which one.

Say I'm editing file foo.c and I find something like

void foo(int n) {  bar(2 * n);}

I put the cursor on bar and hit s-l g g. The resulting call to lsp-find-function correctly finds the file bar.c, containing the definition of bar, and displays it. But it does it in the window previously holdingfoo.c.

I suppose there is some configuration option allowing one to say: "please, open the file you find in another window" but I'm unable to find it and I run out of queries to throw at google for that :)

Note that I did find this question, but the answer there doesn't help me, because introducing rules matching *.c in display-buffer-alist doesn't strike me as a smart thing to do.

Help is worth at least a coffe or a beer next time you happen to be in Rome