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authorLinus Walleij <linus.walleij@linaro.org>2019-01-09 22:51:44 +0100
committerBoris Brezillon <bbrezillon@kernel.org>2019-01-15 18:29:53 +0100
commit663ec3a2c2d02775bc723b20a1af33262f790f50 (patch)
tree7f08f12b0668c80c07379fe45a7dd57548ff5f6a /drivers/mtd
parentLinux 5.0-rc2 (diff)
downloadlinux-663ec3a2c2d02775bc723b20a1af33262f790f50.tar.xz
linux-663ec3a2c2d02775bc723b20a1af33262f790f50.zip
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>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/nand/raw/fsmc_nand.c21
1 files changed, 0 insertions, 21 deletions
diff --git a/drivers/mtd/nand/raw/fsmc_nand.c b/drivers/mtd/nand/raw/fsmc_nand.c
index 325b4414dccc..c9149a37f8f0 100644
--- a/drivers/mtd/nand/raw/fsmc_nand.c
+++ b/drivers/mtd/nand/raw/fsmc_nand.c
@@ -593,23 +593,6 @@ static void fsmc_write_buf_dma(struct fsmc_nand_data *host, const u8 *buf,
dma_xfer(host, (void *)buf, len, DMA_TO_DEVICE);
}
-/* fsmc_select_chip - assert or deassert nCE */
-static void fsmc_ce_ctrl(struct fsmc_nand_data *host, bool assert)
-{
- u32 pc = readl(host->regs_va + FSMC_PC);
-
- if (!assert)
- writel_relaxed(pc & ~FSMC_ENABLE, host->regs_va + FSMC_PC);
- else
- writel_relaxed(pc | FSMC_ENABLE, host->regs_va + FSMC_PC);
-
- /*
- * nCE line changes must be applied before returning from this
- * function.
- */
- mb();
-}
-
/*
* fsmc_exec_op - hook called by the core to execute NAND operations
*
@@ -627,8 +610,6 @@ static int fsmc_exec_op(struct nand_chip *chip, const struct nand_operation *op,
pr_debug("Executing operation [%d instructions]:\n", op->ninstrs);
- fsmc_ce_ctrl(host, true);
-
for (op_id = 0; op_id < op->ninstrs; op_id++) {
instr = &op->instrs[op_id];
@@ -686,8 +667,6 @@ static int fsmc_exec_op(struct nand_chip *chip, const struct nand_operation *op,
}
}
- fsmc_ce_ctrl(host, false);
-
return ret;
}