[PATCH v2] PCI: rcar-host: Remove unused LIST_HEAD(res)

[PATCH v2] PCI: rcar-host: Remove unused LIST_HEAD(res)

[Prabhakar]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Remove the unused LIST_HEAD(res) declaration from rcar_pcie_hw_enable().

The macro instantiation defines an unused 'struct list_head res' variable,
which conflicts with a valid resource loop-local 'struct resource *res'
declaration further down in the function, triggering a compiler variable
shadowing warning:

drivers/pci/controller/pcie-rcar-host.c:357:34: warning: declaration of 'res' shadows a previous local [-Wshadow]
357 |                  struct resource *res = win->res;

Fixes: ce351636c67f75a9 ("PCI: rcar: Add suspend/resume")
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
v1->v2:
- Updated the commit message to include the warning.
- Added the Fixes tag.
- Added Reviewed-by tags for Geert and Marek.
---
 drivers/pci/controller/pcie-rcar-host.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/pci/controller/pcie-rcar-host.c b/drivers/pci/controller/pcie-rcar-host.c
index 213028052aa5..cd9171eebc28 100644
--- a/drivers/pci/controller/pcie-rcar-host.c
+++ b/drivers/pci/controller/pcie-rcar-host.c
@@ -346,7 +346,6 @@ static void rcar_pcie_hw_enable(struct rcar_pcie_host *host)
 	struct rcar_pcie *pcie = &host->pcie;
 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(host);
 	struct resource_entry *win;
-	LIST_HEAD(res);
 	int i = 0;
 
 	/* Try setting 5 GT/s link speed */
-- 
2.54.0

Re: [PATCH v2] PCI: rcar-host: Remove unused LIST_HEAD(res)

[Manivannan Sadhasivam]

On Thu, 21 May 2026 10:12:56 +0100, Prabhakar wrote:
> Remove the unused LIST_HEAD(res) declaration from rcar_pcie_hw_enable().
> 
> The macro instantiation defines an unused 'struct list_head res' variable,
> which conflicts with a valid resource loop-local 'struct resource *res'
> declaration further down in the function, triggering a compiler variable
> shadowing warning:
> 
> [...]

Applied, thanks!

[1/1] PCI: rcar-host: Remove unused LIST_HEAD(res)
      commit: 6ba90ce2069ae923b0ec787aebdf2d786e5d2a58

Best regards,
-- 
Manivannan Sadhasivam <mani@kernel.org>

Re: [PATCH v2] PCI: rcar-host: Remove unused LIST_HEAD(res)

[Bjorn Helgaas]

On Thu, May 21, 2026 at 10:12:56AM +0100, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> Remove the unused LIST_HEAD(res) declaration from rcar_pcie_hw_enable().
> 
> The macro instantiation defines an unused 'struct list_head res' variable,
> which conflicts with a valid resource loop-local 'struct resource *res'
> declaration further down in the function, triggering a compiler variable
> shadowing warning:
> 
> drivers/pci/controller/pcie-rcar-host.c:357:34: warning: declaration of 'res' shadows a previous local [-Wshadow]
> 357 |                  struct resource *res = win->res;
> 
> Fixes: ce351636c67f75a9 ("PCI: rcar: Add suspend/resume")
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> ---
> v1->v2:
> - Updated the commit message to include the warning.
> - Added the Fixes tag.
> - Added Reviewed-by tags for Geert and Marek.
> ---
>  drivers/pci/controller/pcie-rcar-host.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/pcie-rcar-host.c b/drivers/pci/controller/pcie-rcar-host.c
> index 213028052aa5..cd9171eebc28 100644
> --- a/drivers/pci/controller/pcie-rcar-host.c
> +++ b/drivers/pci/controller/pcie-rcar-host.c
> @@ -346,7 +346,6 @@ static void rcar_pcie_hw_enable(struct rcar_pcie_host *host)
>  	struct rcar_pcie *pcie = &host->pcie;
>  	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(host);
>  	struct resource_entry *win;
> -	LIST_HEAD(res);
>  	int i = 0;

Internal Sashiko feedback while backporting this patch:

[Severity: High]
This is a pre-existing issue, but does this function lack bounds checking
for the outbound window index 'i' when configuring PCI resources?

Looking at the loop just below this hunk in rcar_pcie_hw_enable():

	resource_list_for_each_entry(win, &bridge->windows) {
		...
		switch (resource_type(res)) {
		case IORESOURCE_IO:
		case IORESOURCE_MEM:
			rcar_pcie_set_outbound(pcie, i, win);
			i++;
			break;
		}
	}

If the device tree populates bridge->windows with more ranges than the
supported outbound window limit (RCAR_PCI_MAX_RESOURCES, which is 4), it
appears 'i' could exceed the limit. Could this result in an out-of-bounds
hardware register write during the calculation of the register offset in
rcar_pcie_set_outbound()?

Re: [PATCH v2] PCI: rcar-host: Remove unused LIST_HEAD(res)

[Marek Vasut]

On 10/3/26 1:32 AM, Bjorn Helgaas wrote:
> On Thu, May 21, 2026 at 10:12:56AM +0100, Prabhakar wrote:
>> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>>
>> Remove the unused LIST_HEAD(res) declaration from rcar_pcie_hw_enable().
>>
>> The macro instantiation defines an unused 'struct list_head res' variable,
>> which conflicts with a valid resource loop-local 'struct resource *res'
>> declaration further down in the function, triggering a compiler variable
>> shadowing warning:
>>
>> drivers/pci/controller/pcie-rcar-host.c:357:34: warning: declaration of 'res' shadows a previous local [-Wshadow]
>> 357 |                  struct resource *res = win->res;
>>
>> Fixes: ce351636c67f75a9 ("PCI: rcar: Add suspend/resume")
>> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
>> Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
>> ---
>> v1->v2:
>> - Updated the commit message to include the warning.
>> - Added the Fixes tag.
>> - Added Reviewed-by tags for Geert and Marek.
>> ---
>>   drivers/pci/controller/pcie-rcar-host.c | 1 -
>>   1 file changed, 1 deletion(-)
>>
>> diff --git a/drivers/pci/controller/pcie-rcar-host.c b/drivers/pci/controller/pcie-rcar-host.c
>> index 213028052aa5..cd9171eebc28 100644
>> --- a/drivers/pci/controller/pcie-rcar-host.c
>> +++ b/drivers/pci/controller/pcie-rcar-host.c
>> @@ -346,7 +346,6 @@ static void rcar_pcie_hw_enable(struct rcar_pcie_host *host)
>>   	struct rcar_pcie *pcie = &host->pcie;
>>   	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(host);
>>   	struct resource_entry *win;
>> -	LIST_HEAD(res);
>>   	int i = 0;
> 
> Internal Sashiko feedback while backporting this patch:
> 
> [Severity: High]
> This is a pre-existing issue, but does this function lack bounds checking
> for the outbound window index 'i' when configuring PCI resources?
I believe this is addressed in

[PATCH] PCI: rcar-host: Validate IO/MEM resource count in DT ranges property

Thank you.