Hi Ulrich-san, Thank you for your comments! > From: Ulrich Hecht, Sent: Monday, August 2, 2021 8:18 PM > > > On 08/02/2021 7:34 AM Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote: > > > > > > Hi Wolfram-san, Ulrich-san, > > > > > From: Wolfram Sang, Sent: Saturday, July 31, 2021 12:28 AM > > > > > > On Fri, May 14, 2021 at 05:53:18PM +0200, Ulrich Hecht wrote: > > > > The TMIO core sets a very low latency limit (100 us), but when using R-Car > > > > SDHI hosts with SD cards, I have observed typical latencies of around 20-30 > > > > ms. This prevents runtime PM from working properly, and the devices remain > > > > on continuously. > > > > > > > > This patch sets the default latency limit to 100 ms to avoid that. > > > > > > > > Signed-off-by: Ulrich Hecht <uli+renesas@xxxxxxxx> > > > > > > Adding Shimoda-san to CC. > > > > > > Shimoda-san: can you kindly run your SDHI tests with this patch applied? > > > > Sure! > > > > However, I have a question about this patch. > > Would you know how to measure the latencies? > > IIRC I simply put a printk() in default_suspend_ok() that dumps td->suspend_latency_ns and td->resume_latency_ns. Thanks! I could get the latencies. > > I enabled function trace of rpm and checked the log, but I could not observe > > any behavior changes with and without applying this patch. > > So you are saying that for you, the clock is suspended as expected when removing the card, even without this patch? > If so, I wonder if there are variations between boards... I'm sorry, I only observed the trace log. As Wolfram-san mentioned on other email thread, I should check the clk_summary whether the clock is enabled or not. So, I'll test this patch with my test environment tomorrow. > CU > Uli
