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author | Boris Brezillon <boris.brezillon@bootlin.com> | 2018-11-20 11:57:20 +0100 |
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committer | Miquel Raynal <miquel.raynal@bootlin.com> | 2019-02-05 15:39:40 +0100 |
commit | 013e6292aaf5e4b083a50a0f9e17e93628616860 (patch) | |
tree | a15ef0c0f41fb1c14a283e9969a6aab719050ec0 /drivers/mtd/chips | |
parent | 661803b23330daa7839680cca43ab410955c3f10 (diff) | |
download | linux-013e6292aaf5e4b083a50a0f9e17e93628616860.tar.gz |
mtd: rawnand: Simplify the locking
nand_get_device() was complex for apparently no good reason. Let's replace this locking scheme with 2 mutexes: one attached to the controller and another one attached to the chip. Every time the core calls nand_get_device(), it will first lock the chip and if the chip is not suspended, will then lock the controller. nand_release_device() will release both lock in the reverse order. nand_get_device() can sleep, just like the previous implementation, which means you should never call that from an atomic context. We also get rid of - the chip->state field, since all it was used for was flagging the chip as suspended. We replace it by a field called chip->suspended and directly set it from nand_suspend/resume() - the controller->wq and controller->active fields which are no longer needed since the new controller->lock (now a mutex) guarantees that all operations are serialized at the controller level - panic_nand_get_device() which would anyway be a no-op. Talking about panic write, I keep thinking the rawnand implementation is unsafe because there's not negotiation with the controller to know when it's actually done with it's previous operation. I don't intend to fix that here, but that's probably something we should look at, or maybe we should consider dropping the ->_panic_write() implementation Last important change to mention: we now return -EBUSY when someone tries to access a device that as been suspended, and propagate this error to the upper layer. Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Diffstat (limited to 'drivers/mtd/chips')
0 files changed, 0 insertions, 0 deletions