On 12/04/19 5:50 PM, Raul Rangel wrote: > On Fri, Apr 12, 2019 at 09:26:44AM +0300, Adrian Hunter wrote: >> On 12/04/19 1:08 AM, Raul E Rangel wrote: >>> I was debugging a SDHC hardware bug and got tired of having to >>> translate the register values by hand. This patch set makes it so all >>> SDHC register read and write operations can be traced and easily read by >>> a human. >> >> While this might be useful for people unfamiliar with SDHCI, I am not sure >> it should be in the upstream kernel. > Can you help me understand your hesitation? Would you prefer removing the > pretty printing? Or would you prefer not having any trace events at all? It is just cost/benefit. I am not sure the cost of maintaining it is worth the benefit of having it upstream. > The xhci driver has a bunch of pretty print trace events that make it > invaluable when debugging. > https://github.com/torvalds/linux/blob/d7563ca5bfca53398e100eb74345c5d3ef06bf9d/drivers/usb/host/xhci.h#L2160 > >> Also, it doesn't seem ideal for every >> driver to add its own plumbing for such a feature. > What do you mean by every driver having to add it's own plumbing? Any > driver that uses sdhci_readX or sdhci_writeX get the functionality for > free. I/O memory mappings are recorded for devices. e.g. /proc/iomem so it could be possible to add tracing for all I/O memory accesses via readx/writex etc, configurable / filterable by device id.
