On 15/07/2025 03:28, Ping-Ke Shih wrote: > 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. > Yes, of course. >> (4000 * 250 = 1000000 and 3200 * 125 = 400000. I don't know >> why rtw89_read8() in the second patch takes only 125 µs.) > >
