| Message ID | 1359538435-21304-1-git-send-email-s.trumtrar@pengutronix.de |
|---|---|
| State | New |
| Headers | show |
On Wed, Jan 30, 2013 at 10:33:55AM +0100, Steffen Trumtrar wrote: > 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 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). > Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> > Cc: stable@vger.kernel.org Cc: stable@vger.kernel.org # v3.5+ Best regards Uwe
On Wed, Jan 30, 2013 at 10:53:53AM +0100, Uwe Kleine-König wrote: > On Wed, Jan 30, 2013 at 10:33:55AM +0100, Steffen Trumtrar wrote: > > 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 > 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). > > > Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> > > Cc: stable@vger.kernel.org > > Cc: stable@vger.kernel.org # v3.5+ > That is better. I will resend my patch in a sec with a new commit message. Thanks, Steffen
diff --git a/arch/arm/mach-imx/clk-imx25.c b/arch/arm/mach-imx/clk-imx25.c index 5d34f67..0e6dde6 100644 --- a/arch/arm/mach-imx/clk-imx25.c +++ b/arch/arm/mach-imx/clk-imx25.c @@ -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");
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 Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> Cc: stable@vger.kernel.org --- arch/arm/mach-imx/clk-imx25.c | 3 +++ 1 file changed, 3 insertions(+)