Re: [PATCH v5 2/4] clocksource: stm32: only use 32 bits timers

2017-10-18 10:21 GMT+02:00 Julien Thierry [off-list ref]:

On 18/10/17 08:43, Benjamin Gaignard wrote:

quoted

16 bits hardware are not enough accure to be used.
Do no allow them to be probed by tested max counter value.

Signed-off-by: Benjamin Gaignard <redacted>
---
  drivers/clocksource/timer-stm32.c | 23 +++++++++--------------
  1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/clocksource/timer-stm32.c

b/drivers/clocksource/timer-stm32.c
index abff21c..f7e4eec 100644

--- a/drivers/clocksource/timer-stm32.c
+++ b/drivers/clocksource/timer-stm32.c

@@ -81,9 +81,9 @@ static irqreturn_t stm32_clock_event_handler(int irq,

void *dev_id)
  static int __init stm32_clockevent_init(struct device_node *node)
  {
        struct reset_control *rstc;
-       unsigned long max_delta;
-       int ret, bits, prescaler = 1;
+       unsigned long max_arr;
        struct timer_of *to;
+       int ret;
        to = kzalloc(sizeof(*to), GFP_KERNEL);
        if (!to)

@@ -113,26 +113,21 @@ static int __init stm32_clockevent_init(struct

device_node *node)
        /* Detect whether the timer is 16 or 32 bits */
        writel_relaxed(~0U, timer_of_base(to) + TIM_ARR);
-       max_delta = readl_relaxed(timer_of_base(to) + TIM_ARR);
-       if (max_delta == ~0U) {
-               prescaler = 1;
-               bits = 32;
-       } else {
-               prescaler = 1024;
-               bits = 16;
+       max_arr = readl_relaxed(timer_of_base(to) + TIM_ARR);
+       if (max_arr != ~0U) {
+               pr_err("32 bits timer is needed\n");
+               return -EINVAL;

Same as with previous patch, I think "to" should get freed.

Yes I could solve that in the first patch

Also, why is there no function to undo what timer_of_init did? Shouldn't we
be able to free the irqs and unmap the timer io base here?

timer-of doesn't provide deinit function since I will have to do a new version
I will add it.

Benjamin

Cheers,

--
Julien Thierry