you suggest that Rashi is referring to learning before tefiloh. This needs further discussion to reconcile it Rashi on 5b that says not to learn before tefiloh.
shmuel siegel, yerushalayim
1. The Rishonim express surprise at the words of Rashi (5b, DH Samuch). Tosfot 5b DH Ella writes that he does not know what Rashi's source is to say that one may learn before Tefillah and cites a proof that this is permitted from Gemara below 14b that Rav taught Torah before Kerias Shema.
2. The Rosh attempts to reconcile Rashi's opinion and writes that Rashi may specifically be referring to a person who prays in his own Beis ha'Midrash and is not accustomed to going to Shul. Such a person might get carried away with his learning and thereby miss the time for Keri'as Shema and Tefilah, which is why Rashi maintains that he may not learn before Tefilah. It follows that we are not concerned that someone who prays in Shul will forget to do so, and therefore Rashi agrees that he may learn before Tefilah.
3. This approach supports what we wrote in Insights to Berachos 22a, on the words of Rashi (DH Tiken Chatzva). We cited Sefer Beis Yosef (by Rav Avraham Direnfeld) that the students would learn Torah in the morning before Keri'as Shema and Tefilah. According to the Rosh, even Rashi agrees that this is permitted because these students were learning in Shul and therefore would not forget to say Keri'as Shema and Tefilah on time.
Kol Tuv,
Dovid Bloom