[PATCH] PCI: brcmstb: Correctly store and use the output value

[PATCH] PCI: brcmstb: Correctly store and use the output value

[Muhammad Usama Anjum]

brcm_pcie_get_inbound_wins() can return negative error. As
num_inbound_wins is unsigned, we'll be unable to recognize the error.
Hence store return value of brcm_pcie_get_inbound_wins() in ret which is
signed and store result back to num_inbound_wins after confirming that
it isn't negative.

Fixes: 46c981fd60de ("PCI: brcmstb: Refactor for chips with many regular inbound windows")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
---
 drivers/pci/controller/pcie-brcmstb.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 55311dc47615d..054810d7962d7 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -1090,9 +1090,10 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
 	u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_PCIE_RCB_64B_MODE_MASK);
 	writel(tmp, base + PCIE_MISC_MISC_CTRL);
 
-	num_inbound_wins = brcm_pcie_get_inbound_wins(pcie, inbound_wins);
-	if (num_inbound_wins < 0)
-		return num_inbound_wins;
+	ret = brcm_pcie_get_inbound_wins(pcie, inbound_wins);
+	if (ret < 0)
+		return ret;
+	num_inbound_wins = (u8)ret;
 
 	set_inbound_win_registers(pcie, inbound_wins, num_inbound_wins);
 
-- 
2.39.2

Re: [PATCH] PCI: brcmstb: Correctly store and use the output value

[Jim Quinlan]

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On Fri, Sep 6, 2024 at 7:10 AM Muhammad Usama Anjum
<usama.anjum@collabora.com> wrote:
>
> brcm_pcie_get_inbound_wins() can return negative error. As
> num_inbound_wins is unsigned, we'll be unable to recognize the error.
> Hence store return value of brcm_pcie_get_inbound_wins() in ret which is
> signed and store result back to num_inbound_wins after confirming that
> it isn't negative.


Hello Muhammad,
You are correct -- I was asked to make a few variables to be of the
type u8, but I missed having an int (ret) hold the
resultof that call. I believe I am still in the process of submitting
this commit series -- V7 is coming next -- so I will
take your email as a review instead of adding a fixup commit.

Unless Bjorn says that V6 was applied.

Thanks and regards,
Jim Quinlan
Broadcom STB/CM
>
>
> Fixes: 46c981fd60de ("PCI: brcmstb: Refactor for chips with many regular inbound windows")
> Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
> ---
>  drivers/pci/controller/pcie-brcmstb.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> index 55311dc47615d..054810d7962d7 100644
> --- a/drivers/pci/controller/pcie-brcmstb.c
> +++ b/drivers/pci/controller/pcie-brcmstb.c
> @@ -1090,9 +1090,10 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
>         u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_PCIE_RCB_64B_MODE_MASK);
>         writel(tmp, base + PCIE_MISC_MISC_CTRL);
>
> -       num_inbound_wins = brcm_pcie_get_inbound_wins(pcie, inbound_wins);
> -       if (num_inbound_wins < 0)
> -               return num_inbound_wins;
> +       ret = brcm_pcie_get_inbound_wins(pcie, inbound_wins);
> +       if (ret < 0)
> +               return ret;
> +       num_inbound_wins = (u8)ret;
>
>         set_inbound_win_registers(pcie, inbound_wins, num_inbound_wins);
>
> --
> 2.39.2
>

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Re: [PATCH] PCI: brcmstb: Correctly store and use the output value

[Florian Fainelli]

On 9/6/24 11:20, Jim Quinlan wrote:
> On Fri, Sep 6, 2024 at 7:10 AM Muhammad Usama Anjum
> <usama.anjum@collabora.com> wrote:
>>
>> brcm_pcie_get_inbound_wins() can return negative error. As
>> num_inbound_wins is unsigned, we'll be unable to recognize the error.
>> Hence store return value of brcm_pcie_get_inbound_wins() in ret which is
>> signed and store result back to num_inbound_wins after confirming that
>> it isn't negative.
> 
> 
> Hello Muhammad,
> You are correct -- I was asked to make a few variables to be of the
> type u8, but I missed having an int (ret) hold the
> resultof that call. I believe I am still in the process of submitting
> this commit series -- V7 is coming next -- so I will
> take your email as a review instead of adding a fixup commit.
> 
> Unless Bjorn says that V6 was applied.

A similar patch has already been submitted to address this in a slightly 
different way:

https://lore.kernel.org/all/20240904161953.46790-2-riyandhiman14@gmail.com/
-- 
Florian