Twice Mikra with Rashi on Shabbat during Mourning

Is it permitted to study Twice Mikra with Rashi on Shabbat during the days of Shiva?

Written in 'Birkei Yosef', Yoreh De'ah, Siman 378, Paragraph 4: "But to review the Parsha, etc., it seems clear that this applies only to Shnaim Mikra, not Rashi, even if one is accustomed to studying Shnaim Mikra and Rashi every week, still, since it is not a general obligation like the translation, one should not read Rashi on Shabbat during mourning, contrary to what is written otherwise." However, in 'Aruch HaShulchan', Yoreh De'ah, Siman 378, Paragraphs 6 and 7, and I have seen one of the greats who wrote that one who is accustomed to studying 18 chapters of Mishnah every day can study them also on Shabbat during mourning [KN B'Rosh, Siman 75, Letter 57], and according to this, if he has a fixed lesson to study Gemara and Poskim, he can also study on that Shabbat, and if he is accustomed to studying the weekly Parsha with Rashi every Shabbat, he can also study [and so it is written in Baalei HaTurim, Ska 2, in the name of Lef]. And see there that he wrote so, joining the opinion of those who hold that on Shabbat there is no prohibition to study Torah that he cannot study in permissible matters due to the delight of Shabbat.