2012/10/11 Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>: > On Thu, Oct 11, 2012 at 10:39 AM, André Bachmann > <andrebachmann.dd@xxxxxxxxx> wrote: >> Hi all, >> >> here I have a TI Sitara AM335X with its latest SDK v05.05.00. I >> installed it and I'm able to compile my kernels. Kernel 3.2.0 is >> shipped with this SDK. >> >> However, I want to use the official RT patches from >> http://www.kernel.org/pub/linux/kernel/projects/rt/3.2/older/. Since >> kernel 3.2.0 is delivered with this SDK, I chose >> http://www.kernel.org/pub/linux/kernel/projects/rt/3.2/older/patch-3.2-rt10.patch.bz2 >> as the correct patch. With it, I patched my kernel sources - no errors >> here. After that, I checked if there are any problems by compiling >> this patched kernel. No problems, my board still boots fine. >> >> Then I really wanted to use the new RT features, so I backed up the >> default config file tisdk_am335x-evm_defconfig and changed the option >> "CONFIG_PREEMPT_NONE=y" to "CONFIG_PREEMPT_RT_FULL=y". No further >> changes. >> >> If I now compile this, I get an error when compiling drivers/pwm/pwm.c: >> >> ... >> CC drivers/pwm/pwm.o >> drivers/pwm/pwm.c: In function 'pwm_set_frequency': >> drivers/pwm/pwm.c:291:2: error: expected expression before 'do' >> make[3]: *** [drivers/pwm/pwm.o] Error 1 >> make[2]: *** [drivers/pwm] Error 2 >> make[1]: *** [drivers] Error 2 >> make[1]: Leaving directory >> `/home/user/ti-sdk-am335x-evm-05.05.00.00/board-support/linux-3.2.0-psp04.06.00.08.sdk' >> make: *** [linux] Error 2 >> >> This is the function near this line in pwm.c: >> >> 282 int pwm_set_frequency(struct pwm_device *p, unsigned long freq) >> 283 { >> 284 struct pwm_config c; >> 285 >> 286 if (!freq) >> 287 return -EINVAL; >> 288 >> 289 c.config_mask = BIT(PWM_CONFIG_PERIOD_TICKS), >> 290 c.period_ticks = pwm_ns_to_ticks(p, (NSEC_PER_SEC / freq)), > > Nothing to do with RT. Whoever coded up this pwm.c file (presumably > a part of the non-upstream SDK?) should learn the difference between > "," and ";" on the above two lines. > > Paul. > -- Well I must be completely blind to miss this. Thank you! Now the kernel compiles successfully. But now the question arises: Why I don't get this error when not using "CONFIG_PREEMPT_RT_FULL=y"? > >> 291 spin_lock(&p->pwm_lock); >> 292 p->period_ns = NSEC_PER_SEC / freq; >> 293 spin_unlock(&p->pwm_lock); >> 294 return pwm_config(p, &c); >> 295 } >> 296 EXPORT_SYMBOL(pwm_set_frequency); >> >> So the error seems to be related with the call of spin_lock, which >> surely gets changed by the RT patch. Has anyone a hint for me? I'm >> quite new to this matter... :( >> I appreciate any help! >> >> André >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
