[PATCH v3 1/3] ARM: da850: fix infinite loop in clk_set_rate()
Sekhar Nori
nsekhar at ti.com
Tue Dec 6 04:19:20 PST 2016
On Tuesday 06 December 2016 05:28 PM, Bartosz Golaszewski wrote:
> 2016-12-05 11:15 GMT+01:00 Sekhar Nori <nsekhar at ti.com>:
>> On Monday 05 December 2016 03:39 PM, Bartosz Golaszewski wrote:
>>> The aemif clock is added twice to the lookup table in da850.c. This
>>> breaks the children list of pll0_sysclk3 as we're using the same list
>>> links in struct clk. When calling clk_set_rate(), we get stuck in
>>> propagate_rate().
>>>
>>> Create a separate clock for nand, inheriting the rate of the aemif
>>> clock and retrieve it in the davinci_nand module.
>>>
>>> Signed-off-by: Bartosz Golaszewski <bgolaszewski at baylibre.com>
>>> ---
>>> arch/arm/mach-davinci/da850.c | 7 ++++++-
>>> 1 file changed, 6 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
>>> index e770c97..c008e5e 100644
>>> --- a/arch/arm/mach-davinci/da850.c
>>> +++ b/arch/arm/mach-davinci/da850.c
>>> @@ -367,6 +367,11 @@ static struct clk aemif_clk = {
>>> .flags = ALWAYS_ENABLED,
>>> };
>>>
>>> +static struct clk aemif_nand_clk = {
>>> + .name = "nand",
>>> + .parent = &aemif_clk,
>>> +};
>>> +
>>> static struct clk usb11_clk = {
>>> .name = "usb11",
>>> .parent = &pll0_sysclk4,
>>> @@ -537,7 +542,7 @@ static struct clk_lookup da850_clks[] = {
>>> CLK("da830-mmc.0", NULL, &mmcsd0_clk),
>>> CLK("da830-mmc.1", NULL, &mmcsd1_clk),
>>> CLK("ti-aemif", NULL, &aemif_clk),
>>> - CLK(NULL, "aemif", &aemif_clk),
>>> + CLK(NULL, "aemif", &aemif_nand_clk),
>>
>> Why use a NULL device name here?
>
> Hi Sekhar,
>
> there's an issue with this bit. I added an of_dev_auxdata entry to
> da8xx-dt.c for the nand node, but it didn't work (the nand driver
> could not get the clock). When I dug deeper, it turned out, the nand
> node is created from aemif_probe() instead of from
> da850_init_machine() and the lookup table is not passed as argument to
> of_platform_populate().
>
> There are two solutions: one is using "620000000.nand" as dev_id in
> the clock lookup table, but that's ugly. The second is leaving dev_id
> as NULL - I verified that the nand driver works correctly having only
> the connector id. Please let me know which one you prefer or if you
> have other ideas.
Alright, I will take a look at whats going on here. This series will
have to wait for v4.11 anyway.
Thanks,
Sekhar
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