On Fri, 12 Apr 2013, Rabin Vincent wrote: > 2013/4/9 Lee Jones <lee.jo...@linaro.org>: > > Someone has spent a fair amount of effort writing a runtime configuration > > changing algorithm for DMA clients. However, the config appears to never > > actually make it to hardware. In order for the configuration to take hold > > we need to issue a d40_config_write(), as this is the routine which writes > > it into the hardware's registers. > > No, it's not. This function is only for initial configuration which > should only be written when the channel is allocated. In fact, by > calling it here in runtime_config, you are introducing a serious bug: > other logical channels on the same physical channel will stop because of > the SSLNK/SDLNK of the physical channel being zeroed. > > The runtime config already makes it the hardware in the existing code, > via d40_*_cfg().
Sorry Rabin, but the only place I can see the config being written is in d40_config_write(). Can you paste the line of code in d40_*_cfg() which actually writes the config to hardware please? I don't see it. -- Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/