[PATCH V4 0/5] acpi: cppc optimization patches

Prashanth Prakash
2016-02-17T20:21:24Z

Changes in V4:
[1] Added another patch which decides if or when to send a request to the
platform based on the Minimum Request Turnaround Time(MRTT) and Maximum
Periodic Access Rate(MPAR) to make sure the implementation is compliant
to ACPI spec
[2] Fixed the condition for pr_debug message in cppc_chan_tx_done()

Changes in V3: Addressed the review comments from Alexey, Ashwin and Timur

Changes in V2: Fixed compilation error on i386

This series introduces changes to reduce the time required to send a frequency
transition requests to the platform while using the cppc-cpufreq driver.

With these changes we see significant improvement in the average time to send
freq. transition request to the platform. Profiling on an ARM platform showed
that the average transaction time per request reduced from 200us to under 20us.

Ashwin Chaugule (1):
ACPI / CPPC: Optimize PCC Read Write operations

Prashanth Prakash (4):
acpi: cppc: optimized cpc_read and cpc_write
mailbox: pcc: optimized pcc_send_data
acpi: cppc: replace writeX/readX to PCC with relaxed version
acpi/cppc: use MRTT/MPAR to decide if/when a req can be sent

drivers/acpi/cppc_acpi.c | 237 ++++++++++++++++++++++++++++++++++++++---------
drivers/mailbox/pcc.c | 111 ++++++++++++++++++++--
2 files changed, 295 insertions(+), 53 deletions(-)