ARM i.MX25: clk: parent per5_clk to AHB clock
Subsystems (3)
PATCH 1/1 ARM i.MX25: clk: parent per5_clk to AHB clock
The mxc-timer on the imx25 needs to be derived from the AHB clock. If a bootloader reparents this clock to the ipg_clk_highfreq, which according to the datasheet is a valid operation, the system can/will produce lockups/ freezes after some time [1].
This can be forced with code like
while(1)
syscall(SYS_clock_gettime, CLOCK_REALTIME, &tp);This was already fixed with the commit
"i.MX25 GPT clock fix: ensure correct the clock source" [2],
but it seems, that it got lost. So, re-add this to have a correct gpt.
[1]: http://lists.arm.linux.org.uk/lurker/message/20130129.161230.229bda17.en.html
[2]: 2012d9ca2a1381ae3e733330a7f0d1d2f1988bba
--- arch/arm/mach-imx/clk-imx25.c | 3 +++ 1 file changed, 3 insertions(+)
arch/arm/mach-imx/clk-imx25.c +3 -0
@@ -177,6 +177,9 @@ static int __init __mx25_clocks_init(unsigned long osc_rate)pr_err ("i.MX25 clk %d: register failed with %ld\n" , i,PTR_ERR (clk[i])); +/* Clock source for gpt must be derived from AHB */ +clk_set_parent (clk[per5_sel], clk[ahb]); +clk_register_clkdev (clk[ipg],"ipg" ,"imx-gpt.0" );clk_register_clkdev (clk[gpt_ipg_per],"per" ,"imx-gpt.0" );
Signature · 1 line
1.7.10.4
PATCH 1/1 ARM i.MX25: clk: parent per5_clk to AHB clock
Quoted 9 lines · Steffen Trumtrar
The mxc-timer on the imx25 needs to be derived from the AHB clock. If a bootloader reparents this clock to the
ipg_clk_highfreq, which according to the datasheet is a valid operation, the system can/will produce lockups/ freezes after some time [1].This can be forced with code like
while(1) syscall(SYS_clock_gettime, CLOCK_REALTIME, &tp);
Quoted 6 lines
This was already fixed with the commit
"i.MX25 GPT clock fix: ensure correct the clock source" [2],
but it seems, that it got lost. So, re-add this to have a correct gpt.[1]: http://lists.arm.linux.org.uk/lurker/message/20130129.161230.229bda17.en.html
[2]:2012d9ca2a1381ae3e733330a7f0d1d2f1988bba
Instead of the last paragraph I'd write:
This problem was already fixed with commit
2012d9c (i.MX25 GPT clock fix: ensure correct the clock source)
for v3.1-rc2 but this was lost when i.MX was converted to the common clock framework (commit 6bbaec5; ARM i.MX25: implement clocks using common clock framework).
Quoted 2 lines
Signed-off-by Steffen Trumtrar <[email protected]>Cc stable at vger.kernel.org
Best regards
Uwe
Signature · 2 lines
Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |
PATCH 1/1 ARM i.MX25: clk: parent per5_clk to AHB clock
Quoted 22 lines · Uwe Kleine-K?nig
Quoted 9 lines · Steffen Trumtrar
The mxc-timer on the imx25 needs to be derived from the AHB clock. If a bootloader reparents this clock to the
ipg_clk_highfreq, which according to the datasheet is a valid operation, the system can/will produce lockups/ freezes after some time [1].This can be forced with code like
while(1) syscall(SYS_clock_gettime, CLOCK_REALTIME, &tp);Quoted 6 lines
This was already fixed with the commit
"i.MX25 GPT clock fix: ensure correct the clock source" [2],
but it seems, that it got lost. So, re-add this to have a correct gpt.[1]: http://lists.arm.linux.org.uk/lurker/message/20130129.161230.229bda17.en.html
[2]:2012d9ca2a1381ae3e733330a7f0d1d2f1988bbaInstead of the last paragraph I'd write:
This problem was already fixed with commit
2012d9c (i.MX25 GPT clock fix: ensure correct the clock source)
Quoted 9 lines
for v3.1-rc2 but this was lost when i.MX was converted to the common clock framework (commit 6bbaec5; ARM i.MX25: implement clocks using common clock framework).
Quoted 2 lines
Signed-off-by Steffen Trumtrar <[email protected]>Cc stable at vger.kernel.orgCc stable at vger.kernel.org # v3.5+
That is better. I will resend my patch in a sec with a new commit message.
Thanks,
Steffen
Signature · 4 lines
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