Re: [PATCH pinctrl/fixes] pinctrl: aspeed: Fix spurious mux failures on the AST2500

[Andrew Jeffery]

On Thu, 29 Aug 2019, at 16:47, Andrew Jeffery wrote:
> Commit 674fa8daa8c9 ("pinctrl: aspeed-g5: Delay acquisition of regmaps")
> was determined to be a partial fix to the problem of acquiring the LPC
> Host Controller and GFX regmaps: The AST2500 pin controller may need to
> fetch syscon regmaps during expression evaluation as well as when
> setting mux state. For example, this case is hit by attempting to export
> pins exposing the LPC Host Controller as GPIOs.
> 
> An optional eval() hook is added to the Aspeed pinmux operation struct
> and called from aspeed_sig_expr_eval() if the pointer is set by the
> SoC-specific driver. This enables the AST2500 to perform the custom
> action of acquiring its regmap dependencies as required.
> 
> John Wang tested the fix on an Inspur FP5280G2 machine (AST2500-based)
> where the issue was found, and I've booted the fix on Witherspoon
> (AST2500) and Palmetto (AST2400) machines, and poked at relevant pins
> under QEMU by forcing mux configurations via devmem before exporting
> GPIOs to exercise the driver.
> 
> Fixes: 7d29ed88acbb ("pinctrl: aspeed: Read and write bits in LPC and 
> GFX controllers")
> Fixes: 674fa8daa8c9 ("pinctrl: aspeed-g5: Delay acquisition of regmaps")
> Reported-by: John Wang <wangzqbj at inspur.com>
> Tested-by: John Wang <wangzqbj at inspur.com>
> Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
> 

I've applied this change to dev-5.2

Andrew