[U-Boot] [PATCH v3 11/11] mtd: sf: Make sf_mtd.c more robust

[Heiko Schocher]

Hello Boris,

Am 19.11.2018 um 21:59 schrieb Boris Brezillon:
> SPI flash based MTD devs can be registered/unregistered at any time
> through the sf probe command or the spi_flash_free() function.
> 
> This commit does not try to fix the root cause as it would probably
> require rewriting most of the code and have an mtd_info object
> instance per spi_flash object (not to mention that the the spi-flash
> layer is likely to be replaced by a spi-nor layer ported from Linux).
> 
> Instead, we try to be as safe as can be by checking the code returned
> by del_mtd_device() and complain loudly when there's nothing we can
> do about the deregistration failure. When that happens we also reset
> sf_mtd_info.priv to NULL, and check for NULL pointer in the mtd hooks
> so that -ENODEV is returned instead of hitting a NULL pointer
> dereference exception when the MTD instance is later accessed by a user.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon at bootlin.com>
> ---
> Changes in v3:
> - New patch
> ---
>   drivers/mtd/spi/sf_mtd.c | 39 ++++++++++++++++++++++++++++++++++++---
>   1 file changed, 36 insertions(+), 3 deletions(-)

Tested-by: Heiko Schocher <hs at denx.de>

bye,
Heiko
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