On Mon, 2018-03-05 at 20:01 +0200, Jarkko Sakkinen wrote: > On Mon, Mar 05, 2018 at 12:56:33PM +0200, Jarkko Sakkinen wrote: > > On Fri, Mar 02, 2018 at 12:26:35AM +0530, Nayna Jain wrote: > > > > > > > > > On 03/01/2018 02:52 PM, Jarkko Sakkinen wrote: > > > > On Wed, Feb 28, 2018 at 02:18:27PM -0500, Nayna Jain wrote: > > > > > In tpm_transmit, after send(), the code checks for status in a loop > > > > Maybe cutting hairs now but please just use the actual function name > > > > instead of send(). Just makes the commit log more useful asset. > > > Sure, will do. > > > > > > > > > - tpm_msleep(TPM_TIMEOUT); > > > > > + tpm_msleep(TPM_TIMEOUT_POLL); > > > > What about just calling schedule()? > > > I'm not sure what you mean by "schedule()". Are you suggesting instead of > > > using usleep_range(), using something with an even finer grain construct? > > > > > > Thanks & Regards, > > > - Nayna > > > > kernel/sched/core.c > > The question I'm trying ask to is: is it better to sleep such a short > time or just ask scheduler to schedule something else after each > iteration? I still don't understand why scheduling some work would be an improvement. We still need to loop, testing for the TPM command to complete. According to the schedule_hrtimeout_range() function comment, schedule_hrtimeout_range() is both power and performance friendly. What we didn't realize is that the hrtimer *uses* the maximum range to calculate the sleep time, but *may* return earlier based on the minimum time. This patch minimizes the tpm_msleep(). The subsequent patch in this patch set shows that 1 msec isn't fine enough granularity. I still think calling usleep_range() is the right solution, but it needs to be at a finer granularity than tpm_msleep() provides. Mimi
