This commit addresses an issue where the USB core could access an invalid event buffer address during runtime suspend, potentially causing SMMU faults and other memory issues. The problem arises from the following sequence. 1. In dwc3_gadget_suspend, there is a chance of a timeout when moving the USB core to the halt state after clearing the run/stop bit by software. 2. In dwc3_core_exit, the event buffer is cleared regardless of the USB core's status, which may lead to an SMMU faults and other memory issues. if the USB core tries to access the event buffer address.
To prevent this issue, this commit ensures that the event buffer address is not cleared by software when the USB core is active during runtime suspend by checking its status before clearing the buffer address.
Cc: stable@vger.kernel.org Fixes: 89d7f9629946 ("usb: dwc3: core: Skip setting event buffers for host only controllers") Signed-off-by: Selvarasu Ganesan selvarasu.g@samsung.com ---
Changes in v2: - Added separate check for USB controller status before cleaning the event buffer. - Link to v1: https://lore.kernel.org/lkml/20240722145617.537-1-selvarasu.g@samsung.com/ --- drivers/usb/dwc3/core.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 734de2a8bd21..5b67d9bca71b 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -564,10 +564,15 @@ int dwc3_event_buffers_setup(struct dwc3 *dwc) void dwc3_event_buffers_cleanup(struct dwc3 *dwc) { struct dwc3_event_buffer *evt; + u32 reg;
if (!dwc->ev_buf) return;
+ reg = dwc3_readl(dwc->regs, DWC3_DSTS); + if (!(reg & DWC3_DSTS_DEVCTRLHLT)) + return; + evt = dwc->ev_buf;
evt->lpos = 0;
On Thu, Aug 08, 2024, Selvarasu Ganesan wrote:
This commit addresses an issue where the USB core could access an invalid event buffer address during runtime suspend, potentially causing SMMU faults and other memory issues. The problem arises from the following sequence. 1. In dwc3_gadget_suspend, there is a chance of a timeout when moving the USB core to the halt state after clearing the run/stop bit by software. 2. In dwc3_core_exit, the event buffer is cleared regardless of the USB core's status, which may lead to an SMMU faults and
This is a workaround to your specific setup behavior. Please document in the commit message which platforms are impacted.
other memory issues. if the USB core tries to access the event buffer address.To prevent this issue, this commit ensures that the event buffer address is not cleared by software when the USB core is active during runtime suspend by checking its status before clearing the buffer address.
Cc: stable@vger.kernel.org
We can keep the stable tag, but there's no issue with the commit below.
Fixes: 89d7f9629946 ("usb: dwc3: core: Skip setting event buffers for host only controllers") Signed-off-by: Selvarasu Ganesan selvarasu.g@samsung.com
Changes in v2:
- Added separate check for USB controller status before cleaning the event buffer.
- Link to v1: https://urldefense.com/v3/__https://lore.kernel.org/lkml/20240722145617.537-...
drivers/usb/dwc3/core.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 734de2a8bd21..5b67d9bca71b 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -564,10 +564,15 @@ int dwc3_event_buffers_setup(struct dwc3 *dwc) void dwc3_event_buffers_cleanup(struct dwc3 *dwc) { struct dwc3_event_buffer *evt;
- u32 reg;
if (!dwc->ev_buf) return;
Please add comment here why we need this and which platform is impacted should we need to go back and test.
- reg = dwc3_readl(dwc->regs, DWC3_DSTS);
- if (!(reg & DWC3_DSTS_DEVCTRLHLT))
return;- evt = dwc->ev_buf;
evt->lpos = 0; -- 2.17.1
Thanks, Thinh
On 8/10/2024 4:58 AM, Thinh Nguyen wrote:
On Thu, Aug 08, 2024, Selvarasu Ganesan wrote:
This commit addresses an issue where the USB core could access an invalid event buffer address during runtime suspend, potentially causing SMMU faults and other memory issues. The problem arises from the following sequence. 1. In dwc3_gadget_suspend, there is a chance of a timeout when moving the USB core to the halt state after clearing the run/stop bit by software. 2. In dwc3_core_exit, the event buffer is cleared regardless of the USB core's status, which may lead to an SMMU faults and
This is a workaround to your specific setup behavior. Please document in the commit message which platforms are impacted.
Please correct me if i am wrong. I dont think this workaround only applicable our specific setup. It could be a common issue across all other vendor platforms, and it's required to must check the controller status before clear the event buffers address. What you think is it really required to mention the platform details in commit message?
other memory issues. if the USB core tries to access the event buffer address.To prevent this issue, this commit ensures that the event buffer address is not cleared by software when the USB core is active during runtime suspend by checking its status before clearing the buffer address.
Cc: stable@vger.kernel.org
We can keep the stable tag, but there's no issue with the commit below.
By mistaken I mentioned wrong commit ID. The correct commit id would be 660e9bde74d69 ("usb: dwc3: remove num_event_buffers").
Fixes: 89d7f9629946 ("usb: dwc3: core: Skip setting event buffers for host only controllers") Signed-off-by: Selvarasu Ganesan selvarasu.g@samsung.com
Changes in v2:
- Added separate check for USB controller status before cleaning the event buffer.
- Link to v1: https://urldefense.com/v3/__https://lore.kernel.org/lkml/20240722145617.537-...
drivers/usb/dwc3/core.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 734de2a8bd21..5b67d9bca71b 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -564,10 +564,15 @@ int dwc3_event_buffers_setup(struct dwc3 *dwc) void dwc3_event_buffers_cleanup(struct dwc3 *dwc) { struct dwc3_event_buffer *evt;
- u32 reg;
if (!dwc->ev_buf) return;
Please add comment here why we need this and which platform is impacted should we need to go back and test.
Do you want add comment as like below?. If yes, As i said earlier not required to mention our platform name as it could be a common issue across all the other vendor platforms.
/*Prevent USB controller invalid event buffer address access in Exynos platform if USB controller still in active.*/
- reg = dwc3_readl(dwc->regs, DWC3_DSTS);
- if (!(reg & DWC3_DSTS_DEVCTRLHLT))
return;- evt = dwc->ev_buf;
evt->lpos = 0; -- 2.17.1
Thanks, Thinh
On Sat, Aug 10, 2024, Selvarasu Ganesan wrote:
On 8/10/2024 4:58 AM, Thinh Nguyen wrote:
On Thu, Aug 08, 2024, Selvarasu Ganesan wrote:
This commit addresses an issue where the USB core could access an invalid event buffer address during runtime suspend, potentially causing SMMU faults and other memory issues. The problem arises from the following sequence. 1. In dwc3_gadget_suspend, there is a chance of a timeout when moving the USB core to the halt state after clearing the run/stop bit by software. 2. In dwc3_core_exit, the event buffer is cleared regardless of the USB core's status, which may lead to an SMMU faults and
This is a workaround to your specific setup behavior. Please document in the commit message which platforms are impacted.
Please correct me if i am wrong. I dont think this workaround only applicable our specific setup. It could be a common issue across all other vendor platforms, and it's required to must check the controller status before clear the event buffers address. What you think is it really required to mention the platform details in commit message?
How can it be a common issue, the suspend sequence hasn't completed in the dwc3 driver but yet the buffer is no longer accessible? Also, as you noted, we don't know the exact condition for the SMMU fault, and this isn't reproducible all the time.
other memory issues. if the USB core tries to access the event buffer address.To prevent this issue, this commit ensures that the event buffer address is not cleared by software when the USB core is active during runtime suspend by checking its status before clearing the buffer address.
Cc: stable@vger.kernel.org
We can keep the stable tag, but there's no issue with the commit below.
By mistaken I mentioned wrong commit ID. The correct commit id would be 660e9bde74d69 ("usb: dwc3: remove num_event_buffers").
The above commit isn't the issue either. If it is, then the problem should still exist prior to that.
Fixes: 89d7f9629946 ("usb: dwc3: core: Skip setting event buffers for host only controllers") Signed-off-by: Selvarasu Ganesan selvarasu.g@samsung.com
Changes in v2:
- Added separate check for USB controller status before cleaning the event buffer.
- Link to v1: https://urldefense.com/v3/__https://lore.kernel.org/lkml/20240722145617.537-...
drivers/usb/dwc3/core.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 734de2a8bd21..5b67d9bca71b 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -564,10 +564,15 @@ int dwc3_event_buffers_setup(struct dwc3 *dwc) void dwc3_event_buffers_cleanup(struct dwc3 *dwc) { struct dwc3_event_buffer *evt;
- u32 reg;
if (!dwc->ev_buf) return;
Please add comment here why we need this and which platform is impacted should we need to go back and test.
Do you want add comment as like below?. If yes, As i said earlier not required to mention our platform name as it could be a common issue across all the other vendor platforms.
See note above.
/*Prevent USB controller invalid event buffer address access in Exynos platform if USB controller still in active.*/
Perhaps this:
/* * Exynos platforms may not be able to access event buffer if the * controller failed to halt on dwc3_core_exit(). */
BR, Thinh
- reg = dwc3_readl(dwc->regs, DWC3_DSTS);
- if (!(reg & DWC3_DSTS_DEVCTRLHLT))
return;- evt = dwc->ev_buf;
evt->lpos = 0; -- 2.17.1
Thanks, Thinh
On 8/14/2024 4:47 AM, Thinh Nguyen wrote:
On Sat, Aug 10, 2024, Selvarasu Ganesan wrote:
On 8/10/2024 4:58 AM, Thinh Nguyen wrote:
On Thu, Aug 08, 2024, Selvarasu Ganesan wrote:
This commit addresses an issue where the USB core could access an invalid event buffer address during runtime suspend, potentially causing SMMU faults and other memory issues. The problem arises from the following sequence. 1. In dwc3_gadget_suspend, there is a chance of a timeout when moving the USB core to the halt state after clearing the run/stop bit by software. 2. In dwc3_core_exit, the event buffer is cleared regardless of the USB core's status, which may lead to an SMMU faults and
This is a workaround to your specific setup behavior. Please document in the commit message which platforms are impacted.
Please correct me if i am wrong. I dont think this workaround only applicable our specific setup. It could be a common issue across all other vendor platforms, and it's required to must check the controller status before clear the event buffers address. What you think is it really required to mention the platform details in commit message?
How can it be a common issue, the suspend sequence hasn't completed in the dwc3 driver but yet the buffer is no longer accessible? Also, as you noted, we don't know the exact condition for the SMMU fault, and this isn't reproducible all the time.
Agree. Will update platform detail in next version.
other memory issues. if the USB core tries to access the event buffer address.To prevent this issue, this commit ensures that the event buffer address is not cleared by software when the USB core is active during runtime suspend by checking its status before clearing the buffer address.
Cc: stable@vger.kernel.org
We can keep the stable tag, but there's no issue with the commit below.
By mistaken I mentioned wrong commit ID. The correct commit id would be 660e9bde74d69 ("usb: dwc3: remove num_event_buffers").
The above commit isn't the issue either. If it is, then the problem should still exist prior to that.
This issue still persists in older kernels (6.1.X) as well. We believed that it could be a common issue due to the missing condition for checking the controller status in the mentioned commit above. We require this fix in all stable kernel for the Exynos platform. Is it fine to only mention the "Cc" tag in this case?
Fixes: 89d7f9629946 ("usb: dwc3: core: Skip setting event buffers for host only controllers") Signed-off-by: Selvarasu Ganesan selvarasu.g@samsung.com
Changes in v2:
- Added separate check for USB controller status before cleaning the event buffer.
- Link to v1: https://urldefense.com/v3/__https://lore.kernel.org/lkml/20240722145617.537-...
drivers/usb/dwc3/core.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 734de2a8bd21..5b67d9bca71b 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -564,10 +564,15 @@ int dwc3_event_buffers_setup(struct dwc3 *dwc) void dwc3_event_buffers_cleanup(struct dwc3 *dwc) { struct dwc3_event_buffer *evt;
- u32 reg; if (!dwc->ev_buf) return;
Please add comment here why we need this and which platform is impacted should we need to go back and test.
Do you want add comment as like below?. If yes, As i said earlier not required to mention our platform name as it could be a common issue across all the other vendor platforms.
See note above.
Noted.
/*Prevent USB controller invalid event buffer address access in Exynos platform if USB controller still in active.*/
Perhaps this:
/*
- Exynos platforms may not be able to access event buffer if the
- controller failed to halt on dwc3_core_exit().
Thanks for the suggestions. Will update platform detail in next version.
*/
BR, Thinh
- reg = dwc3_readl(dwc->regs, DWC3_DSTS);
- if (!(reg & DWC3_DSTS_DEVCTRLHLT))
return;- evt = dwc->ev_buf; evt->lpos = 0;
-- 2.17.1
Thanks, Thinh
On Wed, Aug 14, 2024, Selvarasu Ganesan wrote:
On 8/14/2024 4:47 AM, Thinh Nguyen wrote:
On Sat, Aug 10, 2024, Selvarasu Ganesan wrote:
On 8/10/2024 4:58 AM, Thinh Nguyen wrote:
On Thu, Aug 08, 2024, Selvarasu Ganesan wrote:
This commit addresses an issue where the USB core could access an invalid event buffer address during runtime suspend, potentially causing SMMU faults and other memory issues. The problem arises from the following sequence. 1. In dwc3_gadget_suspend, there is a chance of a timeout when moving the USB core to the halt state after clearing the run/stop bit by software. 2. In dwc3_core_exit, the event buffer is cleared regardless of the USB core's status, which may lead to an SMMU faults and
This is a workaround to your specific setup behavior. Please document in the commit message which platforms are impacted.
Please correct me if i am wrong. I dont think this workaround only applicable our specific setup. It could be a common issue across all other vendor platforms, and it's required to must check the controller status before clear the event buffers address. What you think is it really required to mention the platform details in commit message?
How can it be a common issue, the suspend sequence hasn't completed in the dwc3 driver but yet the buffer is no longer accessible? Also, as you noted, we don't know the exact condition for the SMMU fault, and this isn't reproducible all the time.
Agree. Will update platform detail in next version.
other memory issues. if the USB core tries to access the event buffer address.To prevent this issue, this commit ensures that the event buffer address is not cleared by software when the USB core is active during runtime suspend by checking its status before clearing the buffer address.
Cc: stable@vger.kernel.org
We can keep the stable tag, but there's no issue with the commit below.
By mistaken I mentioned wrong commit ID. The correct commit id would be 660e9bde74d69 ("usb: dwc3: remove num_event_buffers").
The above commit isn't the issue either. If it is, then the problem should still exist prior to that.
This issue still persists in older kernels (6.1.X) as well. We believed that it could be a common issue due to the missing condition for checking the controller status in the mentioned commit above. We require this fix in all stable kernel for the Exynos platform. Is it fine to only mention the "Cc" tag in this case?
You can just Cc stable and indicate how far you want this to be backported. Make sure to note that this change resolves a hardware quirk.
e.g. Cc: stable stable@kernel.org # 6.1.x
BR, Thinh
On 8/15/2024 5:34 AM, Thinh Nguyen wrote:
On Wed, Aug 14, 2024, Selvarasu Ganesan wrote:
On 8/14/2024 4:47 AM, Thinh Nguyen wrote:
On Sat, Aug 10, 2024, Selvarasu Ganesan wrote:
On 8/10/2024 4:58 AM, Thinh Nguyen wrote:
On Thu, Aug 08, 2024, Selvarasu Ganesan wrote:
This commit addresses an issue where the USB core could access an invalid event buffer address during runtime suspend, potentially causing SMMU faults and other memory issues. The problem arises from the following sequence. 1. In dwc3_gadget_suspend, there is a chance of a timeout when moving the USB core to the halt state after clearing the run/stop bit by software. 2. In dwc3_core_exit, the event buffer is cleared regardless of the USB core's status, which may lead to an SMMU faults and
This is a workaround to your specific setup behavior. Please document in the commit message which platforms are impacted.
Please correct me if i am wrong. I dont think this workaround only applicable our specific setup. It could be a common issue across all other vendor platforms, and it's required to must check the controller status before clear the event buffers address. What you think is it really required to mention the platform details in commit message?
How can it be a common issue, the suspend sequence hasn't completed in the dwc3 driver but yet the buffer is no longer accessible? Also, as you noted, we don't know the exact condition for the SMMU fault, and this isn't reproducible all the time.
Agree. Will update platform detail in next version.
other memory issues. if the USB core tries to access the event buffer address.To prevent this issue, this commit ensures that the event buffer address is not cleared by software when the USB core is active during runtime suspend by checking its status before clearing the buffer address.
Cc: stable@vger.kernel.org
We can keep the stable tag, but there's no issue with the commit below.
By mistaken I mentioned wrong commit ID. The correct commit id would be 660e9bde74d69 ("usb: dwc3: remove num_event_buffers").
The above commit isn't the issue either. If it is, then the problem should still exist prior to that.
This issue still persists in older kernels (6.1.X) as well. We believed that it could be a common issue due to the missing condition for checking the controller status in the mentioned commit above. We require this fix in all stable kernel for the Exynos platform. Is it fine to only mention the "Cc" tag in this case?
You can just Cc stable and indicate how far you want this to be backported. Make sure to note that this change resolves a hardware quirk.
e.g. Cc: stable stable@kernel.org # 6.1.x
Sure. Thanks for the confirmation.
BR, Thinh
On 8/8/2024 5:35 PM, Selvarasu Ganesan wrote:
This commit addresses an issue where the USB core could access an invalid event buffer address during runtime suspend, potentially causing SMMU faults and other memory issues. The problem arises from the following sequence. 1. In dwc3_gadget_suspend, there is a chance of a timeout when moving the USB core to the halt state after clearing the run/stop bit by software. 2. In dwc3_core_exit, the event buffer is cleared regardless of the USB core's status, which may lead to an SMMU faults and other memory issues. if the USB core tries to access the event buffer address.
To prevent this issue, this commit ensures that the event buffer address is not cleared by software when the USB core is active during runtime suspend by checking its status before clearing the buffer address.
Cc: stable@vger.kernel.org Fixes: 89d7f9629946 ("usb: dwc3: core: Skip setting event buffers for host only controllers")
I don't think the fixes tag is right.
This fix is independent of whether controller is host only capable or not. This is fixing the original commit that introduced the cleanup call.
Regards, Krishna,
Signed-off-by: Selvarasu Ganesan selvarasu.g@samsung.com
Changes in v2:
- Added separate check for USB controller status before cleaning the event buffer.
- Link to v1: https://lore.kernel.org/lkml/20240722145617.537-1-selvarasu.g@samsung.com/
drivers/usb/dwc3/core.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 734de2a8bd21..5b67d9bca71b 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -564,10 +564,15 @@ int dwc3_event_buffers_setup(struct dwc3 *dwc) void dwc3_event_buffers_cleanup(struct dwc3 *dwc) { struct dwc3_event_buffer *evt;
- u32 reg;
if (!dwc->ev_buf) return;
- reg = dwc3_readl(dwc->regs, DWC3_DSTS);
- if (!(reg & DWC3_DSTS_DEVCTRLHLT))
return;- evt = dwc->ev_buf;
evt->lpos = 0;
On Mon, Aug 19, 2024, Krishna Kurapati wrote:
On 8/8/2024 5:35 PM, Selvarasu Ganesan wrote:
This commit addresses an issue where the USB core could access an invalid event buffer address during runtime suspend, potentially causing SMMU faults and other memory issues. The problem arises from the following sequence. 1. In dwc3_gadget_suspend, there is a chance of a timeout when moving the USB core to the halt state after clearing the run/stop bit by software. 2. In dwc3_core_exit, the event buffer is cleared regardless of the USB core's status, which may lead to an SMMU faults and other memory issues. if the USB core tries to access the event buffer address.
To prevent this issue, this commit ensures that the event buffer address is not cleared by software when the USB core is active during runtime suspend by checking its status before clearing the buffer address.
Cc: stable@vger.kernel.org Fixes: 89d7f9629946 ("usb: dwc3: core: Skip setting event buffers for host only controllers")
I don't think the fixes tag is right.
This fix is independent of whether controller is host only capable or not. This is fixing the original commit that introduced the cleanup call.
You're reviewing outdated patch. This was brought up to attention prior[*]. The latest patch is v3, which does not have this Fixes tag.
[*] https://lore.kernel.org/linux-usb/8526e46f-30f2-4f24-8874-624b66aa54b1@samsu...
Thanks, Thinh
linux-stable-mirror@lists.linaro.org
-
Krishna Kurapati -
Selvarasu Ganesan -
Thinh Nguyen