> > + dev_dbg(&client->dev, "write reg:0x%x value:0x%x \n", reg, tmp); > > this debug happens on EVERY write! > Please reserve debug prints only to places where something is going wrong ;(
Hi Arjan, Well, let me ask something on this : I would have thought that we could use dev_dbg for debugging purpose, which is not always related to error conditions. In combination with dynamic printk, it can be a very usefull way of providing some diagnostic on a production phone (or nearly product...), just to understand what's going on on the target. Do you really confirm that dbg traces must be reserved for errors? If so, can you explain why? (I thought there was no perf impact after the macro is stripped) In order to do some diagnostics, I would even have wanted to put as much dev_dbg as possible in all critical areas of the code, where there is a lot of control complexity. This, combined with the dynamic debug feature behind the dev_dbg macros could be really helpful. I had asked you the question on dynamic_printk some time ago, where you proposed to activate it by default if we found it to be working. I did not follow up on this, because yes, it's working really fine, but it is using some hash tables to determine if the log is enabled or not. So this may have impact on performance if there are widespread dev_dbg+ dynamic_printk enabled. I was planning to study the real perf impact before going back to you. But if we cannot use dev_dbg for anything else than errors, this study may be useless... Unless you know another way to have dynamic tracing/diagnostic capability without recompiling the kernel? Regards, Sylvain --------------------------------------------------------------------- Intel Corporation SAS (French simplified joint stock company) Registered headquarters: "Les Montalets"- 2, rue de Paris, 92196 Meudon Cedex, France Registration Number: 302 456 199 R.C.S. NANTERRE Capital: 4,572,000 Euros This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies. _______________________________________________ Meego-kernel mailing list [email protected] http://lists.meego.com/listinfo/meego-kernel
