On 1/23/2013 7:07 AM, Tivy, Robert wrote:
>> -----Original Message-----
>> From: Nori, Sekhar
>> Sent: Tuesday, January 22, 2013 4:04 AM
>>
>> Rob,
>>
>> On 1/11/2013 5:53 AM, Robert Tivy wrote:
>>> Added dsp clock definition, keyed to "davinci-rproc.0".
>>>
>>> Signed-off-by: Robert Tivy <rt...@ti.com>
>>> ---
>>> arch/arm/mach-davinci/da850.c | 9 +++++++++
>>> 1 file changed, 9 insertions(+)
>>>
>>> diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-
>> davinci/da850.c
>>> index 097fcb2..50107c5 100644
>>> --- a/arch/arm/mach-davinci/da850.c
>>> +++ b/arch/arm/mach-davinci/da850.c
>>> @@ -375,6 +375,14 @@ static struct clk sata_clk = {
>>> .flags = PSC_FORCE,
>>> };
>>>
>>> +static struct clk dsp_clk = {
>>> + .name = "dsp",
>>> + .parent = &pll0_sysclk1,
>>> + .domain = DAVINCI_GPSC_DSPDOMAIN,
>>> + .lpsc = DA8XX_LPSC0_GEM,
>>> + .flags = PSC_LRST,
>>> +};
>>> +
>>> static struct clk_lookup da850_clks[] = {
>>> CLK(NULL, "ref", &ref_clk),
>>> CLK(NULL, "pll0", &pll0_clk),
>>> @@ -421,6 +429,7 @@ static struct clk_lookup da850_clks[] = {
>>> CLK("spi_davinci.1", NULL, &spi1_clk),
>>> CLK("vpif", NULL, &vpif_clk),
>>> CLK("ahci", NULL, &sata_clk),
>>> + CLK("davinci-rproc.0", NULL, &dsp_clk),
>>
>> Adding this clock node without the having the driver probed leads to
>> kernel hang while booting. With CONFIG_DAVINCI_RESET_CLOCKS=n, the
>> kernel boot fine. It looks like there is some trouble disabling the
>> clock if it is not used. Can you please check this issue?
>>
>> Thanks,
>> Sekhar
>
> Sekhar,
>
> Thankyou for trying that out.
>
> I discovered that the kernel boot hang is caused when trying to disable this
> clk during init, from within the function davinci_clk_disable_unused(). That
> function calls davinci_psc_config() which attempts to disable the DSP clock.
> Since this clk is enabled after reset, disabling it involves a state
> transition, and therefore the function must wait for GOSTAT[1] to be 0. For
> most peripherals this happens automatically, but for the DSP (and ARM, too),
> the DSP must execute the IDLE instruction to allow a clock enable->disable
> transition. Since this is bootup and there is no real program on the DSP
> yet, this doesn't happen.
>
> I was able to overcome this by adding PSC_FORCE to the clk->flags for
> dsp_clk. In fact, without PSC_FORCE I was not able to "rmmod
> davinci_remoteproc" since the firmware file that I'm loading did not execute
> IDLE. It feels like for davinci we should have a way to control the
> clk->flags' PSC_FORCE setting at run-time. The PSC_FORCE would be set
> initially (during boot) and the user (or system integrator) would have a way
> to unset it dynamically. That way, when the DSP firmware does actually have
> a structured way to enter IDLE, the user can say "I'd like a structured
> shutdown" and unset PSC_FORCE (via a clean API). But for now I'm just going
> to turn on PSC_FORCE:
> .flags = PSC_LRST | PSC_FORCE,
Thanks for the debug. It works for me after I added PSC_FORCE. Here is
the patch I am finally committing.
Thanks,
Sekhar
commit 09810a853b9a7920ba8c250d18815ef236effc47
Author: Robert Tivy <rt...@ti.com>
AuthorDate: Thu Jan 10 16:23:22 2013 -0800
Commit: Sekhar Nori <nsek...@ti.com>
CommitDate: Thu Jan 24 10:54:08 2013 +0530
ARM: davinci: da850: add dsp clock definition
Added dsp clock definition, keyed to "davinci-rproc.0".
DSP clocks is derived from pll0 sysclk1. Add a clock tree
node for that too.
Signed-off-by: Robert Tivy <rt...@ti.com>
[nsek...@ti.com: merge addition of pll0 sysclk1 and dsp clock
into one commit. Add PSC_FORCE to dsp clock node to handle the
case where DSP does not go into IDLE and its clock needs to
be disabled.]
Signed-off-by: Sekhar Nori <nsek...@ti.com>
diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
index 6b9154e..0c4a26d 100644
--- a/arch/arm/mach-davinci/da850.c
+++ b/arch/arm/mach-davinci/da850.c
@@ -76,6 +76,13 @@ static struct clk pll0_aux_clk = {
.flags = CLK_PLL | PRE_PLL,
};
+static struct clk pll0_sysclk1 = {
+ .name = "pll0_sysclk1",
+ .parent = &pll0_clk,
+ .flags = CLK_PLL,
+ .div_reg = PLLDIV1,
+};
+
static struct clk pll0_sysclk2 = {
.name = "pll0_sysclk2",
.parent = &pll0_clk,
@@ -368,10 +375,19 @@ static struct clk sata_clk = {
.flags = PSC_FORCE,
};
+static struct clk dsp_clk = {
+ .name = "dsp",
+ .parent = &pll0_sysclk1,
+ .domain = DAVINCI_GPSC_DSPDOMAIN,
+ .lpsc = DA8XX_LPSC0_GEM,
+ .flags = PSC_LRST | PSC_FORCE,
+};
+
static struct clk_lookup da850_clks[] = {
CLK(NULL, "ref", &ref_clk),
CLK(NULL, "pll0", &pll0_clk),
CLK(NULL, "pll0_aux", &pll0_aux_clk),
+ CLK(NULL, "pll0_sysclk1", &pll0_sysclk1),
CLK(NULL, "pll0_sysclk2", &pll0_sysclk2),
CLK(NULL, "pll0_sysclk3", &pll0_sysclk3),
CLK(NULL, "pll0_sysclk4", &pll0_sysclk4),
@@ -413,6 +429,7 @@ static struct clk_lookup da850_clks[] = {
CLK("spi_davinci.1", NULL, &spi1_clk),
CLK("vpif", NULL, &vpif_clk),
CLK("ahci", NULL, &sata_clk),
+ CLK("davinci-rproc.0", NULL, &dsp_clk),
CLK(NULL, NULL, NULL),
};
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