Re: [PATCH] tpm_crb: Remove dead code from crb_map_res()

[Stefano Garzarella <sgarzare@redhat.com>]

On Tue, Sep 01, 2026 at 05:29:46PM +0300, Jarkko Sakkinen wrote:
>In all the pre-existing call sites both @iomem and @iobase_ptr are
>either NULL or non-NULL.

I don't know this code, but I'm a bit worried about iobase_ptr and 
*iobase_ptr. IIUC it is true that iobase_ptr and iores are either NULL 
or non-NULL, but here we are removing the case where *iobase_ptr is 
NULL.

Now looking at crb_map_io(), IIUC iobase_array is initialized with NULL 
pointers and the code we are removing was the only one initializing 
those pointers IIUC, or am I missing something?

Thanks,
Stefano

>
>Thus, add invariant for this and remove a dead basic block.
>
>Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
>---
> drivers/char/tpm/tpm_crb.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
>diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
>index ceb4100ba400..e7a61f36c58b 100644
>--- a/drivers/char/tpm/tpm_crb.c
>+++ b/drivers/char/tpm/tpm_crb.c
>@@ -570,15 +570,12 @@ static void __iomem *crb_map_res(struct device *dev, struct resource *iores,
> 	if (start != new_res.start)
> 		return IOMEM_ERR_PTR(-EINVAL);
>
>+	if ((iores == NULL) != (iobase_ptr == NULL))
>+		return IOMEM_ERR_PTR(-EINVAL);
>+
> 	if (!iores)
> 		return devm_ioremap_resource(dev, &new_res);
>
>-	if (!*iobase_ptr) {
>-		*iobase_ptr = devm_ioremap_resource(dev, iores);
>-		if (IS_ERR(*iobase_ptr))
>-			return *iobase_ptr;
>-	}
>-
> 	return *iobase_ptr + (new_res.start - iores->start);
> }
>
>-- 
>2.47.3
>
>