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Linus Walleij
663ec3a2c2
mtd: rawnand: fsmc: Keep bank enable bit set
Hammering the "bank enable" (PBKEN) bit on and off between every command crashes the Nomadik NHK15 with this message: Scanning device for bad blocks Unhandled fault: external abort on non-linefetch (0x008) at 0xcc95e000 pgd = (ptrval) [cc95e000] *pgd=0b808811, *pte=40000653, *ppte=40000552 Internal error: : 8 [#1] PREEMPT ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 4.20.0-rc2+ #72 Hardware name: Nomadik STn8815 PC is at fsmc_exec_op+0x194/0x204 (...) After a discussion we (me and Boris Brezillon) start to suspect that this bit does not immediately control the chip select line at all, it rather enables access to the bank and the hardware will drive the CS autonomously. If there is a NAND chip connected, we should keep this enabled. As fsmc_nand_setup() sets this bit, we can simply remove the offending code. Fixes: 550b9fc4e3af ("mtd: rawnand: fsmc: Stop implementing ->select_chip()") Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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