Re: [PATCH v2 1/2] net, can, ifi: fix "write buffer full" error

[Marek Vasut]

On 02/08/2018 10:33 PM, Marc Kleine-Budde wrote:
> On 02/08/2018 08:22 PM, Marek Vasut wrote:
>> On 02/08/2018 03:46 PM, Marc Kleine-Budde wrote:
>>> On 02/08/2018 07:47 AM, Heiko Schocher wrote:
 the driver reads in the ISR first the IRQpending register,
 and clears after that in a write *all* bits in it.

 It could happen that the isr register raise bits between
 this 2 register accesses, which leads in lost bits ...

 In case it clears "TX message sent successfully", the driver
 never sends any Tx data, and buffers to userspace run over.

 Fixed this:
 clear only the bits in the IRQpending register, the
 driver had read.

 Signed-off-by: Heiko Schocher 
 Reviewed-by: Marek Vasut 
>>>
>>> Applied both to linux-can.
>>
>> Can you also apply them to stable, so they get into 4.9.x etc ?
> 
> I've already added stable on Cc, so they will be picked up by the stable
> maintainers.

Thanks!

-- 
Best regards,
Marek Vasut

Re: [PATCH v2 1/2] net, can, ifi: fix "write buffer full" error

[Marc Kleine-Budde]

On 02/08/2018 08:22 PM, Marek Vasut wrote:
> On 02/08/2018 03:46 PM, Marc Kleine-Budde wrote:
>> On 02/08/2018 07:47 AM, Heiko Schocher wrote:
>>> the driver reads in the ISR first the IRQpending register,
>>> and clears after that in a write *all* bits in it.
>>>
>>> It could happen that the isr register raise bits between
>>> this 2 register accesses, which leads in lost bits ...
>>>
>>> In case it clears "TX message sent successfully", the driver
>>> never sends any Tx data, and buffers to userspace run over.
>>>
>>> Fixed this:
>>> clear only the bits in the IRQpending register, the
>>> driver had read.
>>>
>>> Signed-off-by: Heiko Schocher 
>>> Reviewed-by: Marek Vasut 
>>
>> Applied both to linux-can.
> 
> Can you also apply them to stable, so they get into 4.9.x etc ?

I've already added stable on Cc, so they will be picked up by the stable
maintainers.

Marc

-- 
Pengutronix e.K.  | Marc Kleine-Budde   |
Industrial Linux Solutions| Phone: +49-231-2826-924 |
Vertretung West/Dortmund  | Fax:   +49-5121-206917- |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |



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Re: [PATCH v2 1/2] net, can, ifi: fix "write buffer full" error

[Marek Vasut]

On 02/08/2018 03:46 PM, Marc Kleine-Budde wrote:
> On 02/08/2018 07:47 AM, Heiko Schocher wrote:
>> the driver reads in the ISR first the IRQpending register,
>> and clears after that in a write *all* bits in it.
>>
>> It could happen that the isr register raise bits between
>> this 2 register accesses, which leads in lost bits ...
>>
>> In case it clears "TX message sent successfully", the driver
>> never sends any Tx data, and buffers to userspace run over.
>>
>> Fixed this:
>> clear only the bits in the IRQpending register, the
>> driver had read.
>>
>> Signed-off-by: Heiko Schocher 
>> Reviewed-by: Marek Vasut 
> 
> Applied both to linux-can.

Can you also apply them to stable, so they get into 4.9.x etc ?

Thanks!

-- 
Best regards,
Marek Vasut

Re: [PATCH v2 1/2] net, can, ifi: fix "write buffer full" error

[Marc Kleine-Budde]

On 02/08/2018 07:47 AM, Heiko Schocher wrote:
> the driver reads in the ISR first the IRQpending register,
> and clears after that in a write *all* bits in it.
> 
> It could happen that the isr register raise bits between
> this 2 register accesses, which leads in lost bits ...
> 
> In case it clears "TX message sent successfully", the driver
> never sends any Tx data, and buffers to userspace run over.
> 
> Fixed this:
> clear only the bits in the IRQpending register, the
> driver had read.
> 
> Signed-off-by: Heiko Schocher 
> Reviewed-by: Marek Vasut 

Applied both to linux-can.

Tnx,
Marc

-- 
Pengutronix e.K.  | Marc Kleine-Budde   |
Industrial Linux Solutions| Phone: +49-231-2826-924 |
Vertretung West/Dortmund  | Fax:   +49-5121-206917- |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |



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[PATCH v2 1/2] net, can, ifi: fix "write buffer full" error

[Heiko Schocher]

the driver reads in the ISR first the IRQpending register,
and clears after that in a write *all* bits in it.

It could happen that the isr register raise bits between
this 2 register accesses, which leads in lost bits ...

In case it clears "TX message sent successfully", the driver
never sends any Tx data, and buffers to userspace run over.

Fixed this:
clear only the bits in the IRQpending register, the
driver had read.

Signed-off-by: Heiko Schocher 
Reviewed-by: Marek Vasut 
---

Changes in v2:
- add Reviewed-by from Marek

 drivers/net/can/ifi_canfd/ifi_canfd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/ifi_canfd/ifi_canfd.c 
b/drivers/net/can/ifi_canfd/ifi_canfd.c
index 2772d05ff11c..05feb8177936 100644
--- a/drivers/net/can/ifi_canfd/ifi_canfd.c
+++ b/drivers/net/can/ifi_canfd/ifi_canfd.c
@@ -607,7 +607,7 @@ static irqreturn_t ifi_canfd_isr(int irq, void *dev_id)
return IRQ_NONE;
 
/* Clear all pending interrupts but ErrWarn */
-   writel(clr_irq_mask, priv->base + IFI_CANFD_INTERRUPT);
+   writel(isr & clr_irq_mask, priv->base + IFI_CANFD_INTERRUPT);
 
/* RX IRQ or bus warning, start NAPI */
if (isr & rx_irq_mask) {
-- 
2.14.3