Mike, >From: Mike Chan [mailto:m...@android.com] >Sent: Thursday, June 18, 2009 1:42 PM > > >+ /* Kick DLL state machine if lock not started */ >+kick_dll: >+ ldr r4, sdrc_dlla_ctrl /* get dlla addr */ >+ ldr r5, [r4] /* grab value */ >+ mov r6, r5 /* save value */ > >Richard, could this be done in one instruction, eliminating the need for the >r5 >temporary register? Or was this done intentionally?
Its on purpose I suppose, perhaps there is an optimization. Above I want to make sure I restore the value I came in with for dlla_ctrl. I save off value in r5 for this. Below I clear and set dllidle bit. I don't take the time to figure out if it was set or not coming into function. I saved off value in r5 to allow for this. It is legal for it to be set or cleared in normal operation. The below set/clear needs to happen as 2 writes. The 3rd write is a restore. You could be mindful of input value and perhaps not do a 3rd write but my guess is that will take more code then it saves. >+ orr r6, r6, #0x10 /* dllidle on */ >+ str r6, [r4] >+ dsb >+ bic r6, #0x10 /* dllidle off */ >+ str r6, [r4] >+ dsb >+ str r6, [r4] /* restore old value */ >+ b wait_dll_lock_timed >+ Regards, Richard W. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
