[PATCH v4] xhci: tegra: fix checked USB2 port number

[PATCH v4] xhci: tegra: fix checked USB2 port number

[Henry Lin]

If USB virtualizatoin is enabled, USB2 ports are shared between all
Virtual Functions. The USB2 port number owned by an USB2 root hub in
a Virtual Function may be less than total USB2 phy number supported
by the Tegra XUSB controller.

Using total USB2 phy number as port number to check all PORTSC values
would cause invalid memory access.

[  116.923438] Unable to handle kernel paging request at virtual address 006c622f7665642f
...
[  117.213640] Call trace:
[  117.216783]  tegra_xusb_enter_elpg+0x23c/0x658
[  117.222021]  tegra_xusb_runtime_suspend+0x40/0x68
[  117.227260]  pm_generic_runtime_suspend+0x30/0x50
[  117.232847]  __rpm_callback+0x84/0x3c0
[  117.237038]  rpm_suspend+0x2dc/0x740
[  117.241229] pm_runtime_work+0xa0/0xb8
[  117.245769]  process_scheduled_works+0x24c/0x478
[  117.251007]  worker_thread+0x23c/0x328
[  117.255547]  kthread+0x104/0x1b0
[  117.259389]  ret_from_fork+0x10/0x20
[  117.263582] Code: 54000222 f9461ae8 f8747908 b4ffff48 (f9400100)

Cc: <stable@vger.kernel.org> # v6.3+
Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls")
Signed-off-by: Henry Lin <henryl@nvidia.com>
---
V1 -> V2: Add Fixes tag and the cc stable line
V2 -> V3: Update commit message to clarify issue
V3 -> V4: Resend for patch changelogs that are missing in V3

 drivers/usb/host/xhci-tegra.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
index 6246d5ad1468..76f228e7443c 100644
--- a/drivers/usb/host/xhci-tegra.c
+++ b/drivers/usb/host/xhci-tegra.c
@@ -2183,7 +2183,7 @@ static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool runtime)
 		goto out;
 	}
 
-	for (i = 0; i < tegra->num_usb_phys; i++) {
+	for (i = 0; i < xhci->usb2_rhub.num_ports; i++) {
 		if (!xhci->usb2_rhub.ports[i])
 			continue;
 		portsc = readl(xhci->usb2_rhub.ports[i]->addr);
-- 
2.25.1

Re: [PATCH v4] xhci: tegra: fix checked USB2 port number

[Thierry Reding]

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On Mon, Oct 14, 2024 at 12:21:34PM +0800, Henry Lin wrote:
> If USB virtualizatoin is enabled, USB2 ports are shared between all
> Virtual Functions. The USB2 port number owned by an USB2 root hub in
> a Virtual Function may be less than total USB2 phy number supported
> by the Tegra XUSB controller.
> 
> Using total USB2 phy number as port number to check all PORTSC values
> would cause invalid memory access.
> 
> [  116.923438] Unable to handle kernel paging request at virtual address 006c622f7665642f
> ...
> [  117.213640] Call trace:
> [  117.216783]  tegra_xusb_enter_elpg+0x23c/0x658
> [  117.222021]  tegra_xusb_runtime_suspend+0x40/0x68
> [  117.227260]  pm_generic_runtime_suspend+0x30/0x50
> [  117.232847]  __rpm_callback+0x84/0x3c0
> [  117.237038]  rpm_suspend+0x2dc/0x740
> [  117.241229] pm_runtime_work+0xa0/0xb8
> [  117.245769]  process_scheduled_works+0x24c/0x478
> [  117.251007]  worker_thread+0x23c/0x328
> [  117.255547]  kthread+0x104/0x1b0
> [  117.259389]  ret_from_fork+0x10/0x20
> [  117.263582] Code: 54000222 f9461ae8 f8747908 b4ffff48 (f9400100)
> 
> Cc: <stable@vger.kernel.org> # v6.3+
> Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls")
> Signed-off-by: Henry Lin <henryl@nvidia.com>
> ---
> V1 -> V2: Add Fixes tag and the cc stable line
> V2 -> V3: Update commit message to clarify issue
> V3 -> V4: Resend for patch changelogs that are missing in V3
> 
>  drivers/usb/host/xhci-tegra.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
> index 6246d5ad1468..76f228e7443c 100644
> --- a/drivers/usb/host/xhci-tegra.c
> +++ b/drivers/usb/host/xhci-tegra.c
> @@ -2183,7 +2183,7 @@ static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool runtime)
>  		goto out;
>  	}
>  
> -	for (i = 0; i < tegra->num_usb_phys; i++) {
> +	for (i = 0; i < xhci->usb2_rhub.num_ports; i++) {
>  		if (!xhci->usb2_rhub.ports[i])
>  			continue;
>  		portsc = readl(xhci->usb2_rhub.ports[i]->addr);

Given that the size of usb2_rhub.ports is given by usb2_rhub.num_ports,
this seems the right thing to do regardless of virtualization.

Acked-by: Thierry Reding <treding@nvidia.com>

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