2021-07-02 06:04:43

by Greg Thelen

[permalink] [raw]
Subject: [PATCH] usb: xhci: avoid renesas_usb_fw.mem when it's unusable

Commit a66d21d7dba8 ("usb: xhci: Add support for Renesas controller with
memory") added renesas_usb_fw.mem firmware reference to xhci-pci. Thus
modinfo indicates xhci-pci.ko has "firmware: renesas_usb_fw.mem". But
the firmware is only actually used with CONFIG_USB_XHCI_PCI_RENESAS. An
unusable firmware reference can trigger safety checkers which look for
drivers with unmet firmware dependencies.

Avoid referring to renesas_usb_fw.mem in circumstances when it cannot be
loaded (when CONFIG_USB_XHCI_PCI_RENESAS isn't set).

Signed-off-by: Greg Thelen <[email protected]>
---
drivers/usb/host/xhci-pci.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 18c2bbddf080..cb148da7a789 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -618,8 +618,10 @@ static void xhci_pci_shutdown(struct usb_hcd *hcd)
/*-------------------------------------------------------------------------*/

static const struct xhci_driver_data reneses_data = {
+#if IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS)
.quirks = XHCI_RENESAS_FW_QUIRK,
.firmware = "renesas_usb_fw.mem",
+#endif
};

/* PCI driver selection metadata; PCI hotplugging uses this */
@@ -636,7 +638,13 @@ static const struct pci_device_id pci_ids[] = {
{ /* end: all zeroes */ }
};
MODULE_DEVICE_TABLE(pci, pci_ids);
+/*
+ * Without CONFIG_USB_XHCI_PCI_RENESAS renesas_xhci_check_request_fw() won't
+ * load firmware, so don't encumber the xhci-pci driver with it.
+ */
+#if IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS)
MODULE_FIRMWARE("renesas_usb_fw.mem");
+#endif

/* pci driver glue; this is a "new style" PCI driver module */
static struct pci_driver xhci_pci_driver = {
--
2.32.0.93.g670b81a890-goog


2021-07-02 06:05:47

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH] usb: xhci: avoid renesas_usb_fw.mem when it's unusable

On Thu, Jul 01, 2021 at 10:47:54PM -0700, Greg Thelen wrote:
> Commit a66d21d7dba8 ("usb: xhci: Add support for Renesas controller with
> memory") added renesas_usb_fw.mem firmware reference to xhci-pci. Thus
> modinfo indicates xhci-pci.ko has "firmware: renesas_usb_fw.mem". But
> the firmware is only actually used with CONFIG_USB_XHCI_PCI_RENESAS. An
> unusable firmware reference can trigger safety checkers which look for
> drivers with unmet firmware dependencies.
>
> Avoid referring to renesas_usb_fw.mem in circumstances when it cannot be
> loaded (when CONFIG_USB_XHCI_PCI_RENESAS isn't set).
>
> Signed-off-by: Greg Thelen <[email protected]>
> ---
> drivers/usb/host/xhci-pci.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
> index 18c2bbddf080..cb148da7a789 100644
> --- a/drivers/usb/host/xhci-pci.c
> +++ b/drivers/usb/host/xhci-pci.c
> @@ -618,8 +618,10 @@ static void xhci_pci_shutdown(struct usb_hcd *hcd)
> /*-------------------------------------------------------------------------*/
>
> static const struct xhci_driver_data reneses_data = {
> +#if IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS)

If this is not enabled, why is the whole structure needed?

> .quirks = XHCI_RENESAS_FW_QUIRK,
> .firmware = "renesas_usb_fw.mem",
> +#endif
> };
>
> /* PCI driver selection metadata; PCI hotplugging uses this */
> @@ -636,7 +638,13 @@ static const struct pci_device_id pci_ids[] = {
> { /* end: all zeroes */ }
> };
> MODULE_DEVICE_TABLE(pci, pci_ids);
> +/*
> + * Without CONFIG_USB_XHCI_PCI_RENESAS renesas_xhci_check_request_fw() won't
> + * load firmware, so don't encumber the xhci-pci driver with it.
> + */
> +#if IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS)
> MODULE_FIRMWARE("renesas_usb_fw.mem");
> +#endif

Why not just have this one chunk, why is the first chunk needed?

And a blank line please before your comment?

And can you add a Fixes: line to the changelog text when you resend?

thanks,

greg k-h

2021-07-02 07:13:29

by Greg Thelen

[permalink] [raw]
Subject: Re: [PATCH] usb: xhci: avoid renesas_usb_fw.mem when it's unusable

Greg Kroah-Hartman <[email protected]> wrote:

> On Thu, Jul 01, 2021 at 10:47:54PM -0700, Greg Thelen wrote:
>> Commit a66d21d7dba8 ("usb: xhci: Add support for Renesas controller with
>> memory") added renesas_usb_fw.mem firmware reference to xhci-pci. Thus
>> modinfo indicates xhci-pci.ko has "firmware: renesas_usb_fw.mem". But
>> the firmware is only actually used with CONFIG_USB_XHCI_PCI_RENESAS. An
>> unusable firmware reference can trigger safety checkers which look for
>> drivers with unmet firmware dependencies.
>>
>> Avoid referring to renesas_usb_fw.mem in circumstances when it cannot be
>> loaded (when CONFIG_USB_XHCI_PCI_RENESAS isn't set).
>>
>> Signed-off-by: Greg Thelen <[email protected]>
>> ---
>> drivers/usb/host/xhci-pci.c | 8 ++++++++
>> 1 file changed, 8 insertions(+)
>>
>> diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
>> index 18c2bbddf080..cb148da7a789 100644
>> --- a/drivers/usb/host/xhci-pci.c
>> +++ b/drivers/usb/host/xhci-pci.c
>> @@ -618,8 +618,10 @@ static void xhci_pci_shutdown(struct usb_hcd *hcd)
>> /*-------------------------------------------------------------------------*/
>>
>> static const struct xhci_driver_data reneses_data = {
>> +#if IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS)
>
> If this is not enabled, why is the whole structure needed?

Removing the struct meant 2 more #if guards needed below to initialize
pci_ids, which exceeded my taste.

>> .quirks = XHCI_RENESAS_FW_QUIRK,
>> .firmware = "renesas_usb_fw.mem",
>> +#endif
>> };
>>
>> /* PCI driver selection metadata; PCI hotplugging uses this */
>> @@ -636,7 +638,13 @@ static const struct pci_device_id pci_ids[] = {
>> { /* end: all zeroes */ }
>> };
>> MODULE_DEVICE_TABLE(pci, pci_ids);
>> +/*
>> + * Without CONFIG_USB_XHCI_PCI_RENESAS renesas_xhci_check_request_fw() won't
>> + * load firmware, so don't encumber the xhci-pci driver with it.
>> + */
>> +#if IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS)
>> MODULE_FIRMWARE("renesas_usb_fw.mem");
>> +#endif
>
> Why not just have this one chunk, why is the first chunk needed?

It seemed cleaner to remove both renesas_usb_fw.mem references rather
than leave one unusable one in reneses_data above. But a simpler patch
is appealing, especially given the number of #if guards needed to remove
reneses_data. Patch V2 will just go with this 1-hunk approach.

> And a blank line please before your comment?

Will do.

> And can you add a Fixes: line to the changelog text when you resend?

Will do.

> thanks,
>
> greg k-h

2021-07-02 07:14:49

by Greg Thelen

[permalink] [raw]
Subject: [PATCH V2] usb: xhci: avoid renesas_usb_fw.mem when it's unusable

Commit a66d21d7dba8 ("usb: xhci: Add support for Renesas controller with
memory") added renesas_usb_fw.mem firmware reference to xhci-pci. Thus
modinfo indicates xhci-pci.ko has "firmware: renesas_usb_fw.mem". But
the firmware is only actually used with CONFIG_USB_XHCI_PCI_RENESAS. An
unusable firmware reference can trigger safety checkers which look for
drivers with unmet firmware dependencies.

Avoid referring to renesas_usb_fw.mem in circumstances when it cannot be
loaded (when CONFIG_USB_XHCI_PCI_RENESAS isn't set).

Fixes: a66d21d7dba8 ("usb: xhci: Add support for Renesas controller with memory")
Signed-off-by: Greg Thelen <[email protected]>
---
Changelog since v1:
- Smaller patch, only filters out MODULE_FIRMWARE()
- Added blank line
- Added Fixes footer to commit log

drivers/usb/host/xhci-pci.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 18c2bbddf080..1c9a7957c45c 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -636,7 +636,14 @@ static const struct pci_device_id pci_ids[] = {
{ /* end: all zeroes */ }
};
MODULE_DEVICE_TABLE(pci, pci_ids);
+
+/*
+ * Without CONFIG_USB_XHCI_PCI_RENESAS renesas_xhci_check_request_fw() won't
+ * load firmware, so don't encumber the xhci-pci driver with it.
+ */
+#if IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS)
MODULE_FIRMWARE("renesas_usb_fw.mem");
+#endif

/* pci driver glue; this is a "new style" PCI driver module */
static struct pci_driver xhci_pci_driver = {
--
2.32.0.93.g670b81a890-goog