Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx> wrote: > On 14/07/2025 05:49, Ping-Ke Shih wrote: > > Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx> wrote: > >> This read_poll_timeout_atomic() with a delay of 1 µs and a timeout of > >> 1000000 µs can take ~250 seconds in the worst case because sending a > >> USB control message takes ~250 µs. > > > > I was not aware of the change of [1]. The behavior of atomic version becomes > > different from non-atomic version. > > > > For this patch, I feel we can keep delay_us to 1 and treat timeout_us as > > 'count', which USB devices do smaller retries. The smaller delay_us can > > reduce total polling time, especially for PCIE devices (see my comments below) > > > > Though I don't measure total polling time of patch 2/2, I feel we can apply > > similar idea. > > > > Yes, a smaller timeout also works. I tested 4000 for this patch and 3200 > for patch 2. Forgot to say, for PCIE devices please keep the timeout as was. > (4000 * 250 = 1000000 and 3200 * 125 = 400000. I don't know > why rtw89_read8() in the second patch takes only 125 µs.)
