Re: [PATCH 2/3] PCI: endpoint: pci-epf-test: Handle -ENOSPC in subrange map test

[Niklas Cassel]

On Wed, Mar 18, 2026 at 03:46:28PM +0100, Christian Bruel wrote:
> Report pci_epc_set_bar() -ENOSPC failure with the
> STATUS_BAR_SUBRANGE_SETUP_NOSPC status bit. This can be used to
> skip the subrange test if there is not enough iATU resources to
> allocate it.
> 
> Link: 
> https://lore.kernel.org/linux-pci/20260317152707.GA85951@bhelgaas/T/#m87e4c24173097a0ea70195b71aab294ad8d6c283

I would drop the link.


> Signed-off-by: Christian Bruel <christian.br...@foss.st.com>
> ---
>  drivers/pci/endpoint/functions/pci-epf-test.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c 
> b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 
> 14e61ebe1f116ce04789b6f4c3e965296701ec53..6437f08f0cd4bd4645e380c915b7cf81e66b7c35
>  100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -54,6 +54,7 @@
>  #define STATUS_BAR_SUBRANGE_SETUP_FAIL               BIT(15)
>  #define STATUS_BAR_SUBRANGE_CLEAR_SUCCESS    BIT(16)
>  #define STATUS_BAR_SUBRANGE_CLEAR_FAIL               BIT(17)
> +#define STATUS_BAR_SUBRANGE_SETUP_NOSPC              BIT(18)

Perhaps STATUS_BAR_SUBRANGE_SETUP_SKIP ?

>  
>  #define FLAG_USE_DMA                 BIT(0)
>  
> @@ -903,6 +904,8 @@ static void pci_epf_test_bar_subrange_setup(struct 
> pci_epf_test *epf_test,
>               dev_err(&epf->dev, "pci_epc_set_bar() failed: %d\n", ret);
>               bar->submap = old_submap;
>               bar->num_submap = old_nsub;
> +             if (ret == -ENOSPC)
> +                     status |= STATUS_BAR_SUBRANGE_SETUP_NOSPC;
>               kfree(submap);
>               goto err;
>       }

Here you will have both STATUS_BAR_SUBRANGE_SETUP_NOSPC and
STATUS_BAR_SUBRANGE_SETUP_FAIL set.

Usually, we only have one bit set.


Perhaps something like:

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c 
b/drivers/pci/endpoint/functions/pci-epf-test.c
index 582938b7b4f1..36e5d22f79ab 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -895,6 +895,10 @@ static void pci_epf_test_bar_subrange_setup(struct 
pci_epf_test *epf_test,
                bar->submap = old_submap;
                bar->num_submap = old_nsub;
                kfree(submap);
+               if (ret == -ENOSPC) {
+                       status |= STATUS_BAR_SUBRANGE_SETUP_SKIP;
+                       goto err_status_set;
+               }
                goto err;
        }
        kfree(old_submap);
@@ -918,6 +922,7 @@ static void pci_epf_test_bar_subrange_setup(struct 
pci_epf_test *epf_test,
 
 err:
        status |= STATUS_BAR_SUBRANGE_SETUP_FAIL;
+err_status_set:
        reg->status = cpu_to_le32(status);
 }



This patch should probably be 1/3.


Kind regards,
Niklas