On Thu, Sep 19, 2024 at 11:43 AM Billy Tsai <billy_tsai@xxxxxxxxxxxxxx> wrote: > Performing a dummy read ensures that the register write operation is fully > completed, mitigating any potential bus delays that could otherwise impact > the frequency of bitbang usage. E.g., if the JTAG application uses GPIO to > control the JTAG pins (TCK, TMS, TDI, TDO, and TRST), and the application > sets the TCK clock to 1 MHz, the GPIO’s high/low transitions will rely on > a delay function to ensure the clock frequency does not exceed 1 MHz. > However, this can lead to rapid toggling of the GPIO because the write > operation is POSTed and does not wait for a bus acknowledgment. > > Signed-off-by: Billy Tsai <billy_tsai@xxxxxxxxxxxxxx> If this applies cleanly on mainline I think it should go into fixes as-is. Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Yours, Linus Walleij
