Re: [PATCH v2 05/13] efi: Use a fixed value for the timer clock

[Heinrich Schuchardt]

On 2/22/23 20:12, Simon Glass wrote:

It is not yet clear how to read the timer via EFI. The current value seems
much too high on a Framework laptop I tried. Adjust it to a lower
hard-coded value for now.

Signed-off-by: Simon Glass <s...@chromium.org>
---

(no changes since v1)

  drivers/timer/tsc_timer.c | 4 ++++
  1 file changed, 4 insertions(+)

diff --git a/drivers/timer/tsc_timer.c b/drivers/timer/tsc_timer.c
index 192c7b71a5a..1d2a3f20e4e 100644
--- a/drivers/timer/tsc_timer.c
+++ b/drivers/timer/tsc_timer.c
@@ -404,6 +404,10 @@ static void tsc_timer_ensure_setup(bool early)
        if (!gd->arch.clock_rate) {
                unsigned long fast_calibrate;

+               if (IS_ENABLED(CONFIG_EFI_APP)) {

This needs a code comment telling why you use this 2.75 GHz value.

Why would none of the methods in tsc_timer_ensure_setup() work correctly
in the EFI  app?

Best regards

Heinrich

+                       fast_calibrate = 2750;
+                       goto done;
+               }
                fast_calibrate = native_calibrate_tsc();
                if (fast_calibrate)
                        goto done;