On Wed, Jun 18, 2014 at 04:24:39PM -0500, Scott Wood wrote:
On Wed, 2014-06-18 at 09:55 +0200, Heiko Schocher wrote:
Hello Scott,
[snip]
history to see what Linux version corresponded to the last mtd sync, and generate a diff relative to that.
I think, we should have the linux code as the reference, and on top of this, we should add our U-Boot changes ... Thats the reason for the git tree [1].
One of the strengths of version control is the ability to do three-way merges, rather than throw away the downstream code and reassemble it from scratch.
Indeed.
[snip]
What does #ifndef __UBOOT__ tell you that a diff between the U-Boot and Linux files, as of the SHA1 that was last merged into U-Boot, doesn't tell you?
There we have the "simple copy from linux patch" [2]. It overwrites the U-Boot specific changes, yes, but only in an intermediate step in this git tree ... (Maybe I should add in the commit message, that this is a simple copy from linux sources)
Then a U-Boot specifc patch [3], which introduces again hopefully all U-Boot specific changes... so *all* U-Boot specific changs are documented. At last a seperate licencse file patch [4] added which changes the license text.
My hope was, that future linux mtd syncs could look like:
a) copy new linux source files to u-boot tree [1] (make a new branch go back to commit [2] ... and copy new files from linux) (commit this, to have all linux changes since last sync with linux documented) b) apply [3] and fix problems All U-Boot changes documented c) apply [4] and fix problems d) add newly added U-Boot specific patches (mark them with _UBOOT_ define if they are not yet marked with it) (maybe squash them to step b ?)
-> new git tree readye) squash all patches into one patch and send it to mainline ... so the mainline patch has only new changes with all U-Boot specific changes.
If you take over as NAND custodian, you can of course do the updates as you please (unless Tom or Wolfgang disagree), but until then I insist on doing a proper merge, and not littering the code with #ifndef __UBOOT__.
Thats sounds easy ... and you have all linux and all U-Boot changes visible and documented ... I must admit, I did not tried your proposal to look into the linux changes since the last mtd sync ... but that sounds the more tricky way to get this sync, as the history can be long ... and shouldn;t be the result the same?
Why does the length of the history matter? I'm not asking you to go patch by patch. Just take a diff between the SHA1 of last merge and the SHA1 you want to merge now, and apply that patch.
But it's not even that hard to do so! git format-patch -o mtd-resync v3.7..v3.14 drivers/mtd/nand will give you only the relevant patches, and they should mostly apply, and then you can squash them after the fact.