* [PATCH] bcma: get SoC device struct & assign dma_mask
@ 2022-01-07 4:17 Florian Fainelli
2022-01-10 9:09 ` Christoph Hellwig
0 siblings, 1 reply; 4+ messages in thread
From: Florian Fainelli @ 2022-01-07 4:17 UTC (permalink / raw)
To: linux-mips
Cc: Rafał Miłecki, Florian Fainelli, Christoph Hellwig,
Linus Walleij
From: Rafał Miłecki <rafal@milecki.pl>
For bus devices to be fully usable it's required to set their DMA
parameters.
For years it has been missing and remained unnoticed because of
mips_dma_alloc_coherent() silently handling the empty coherent_dma_mask.
Kernel 4.19 came with a lot of DMA changes and caused a regression on
the bcm47xx. Starting with the commit f8c55dc6e828 ("MIPS: use generic
dma noncoherent ops for simple noncoherent platforms") DMA coherent
allocations just fail. Example:
[ 1.114914] bgmac_bcma bcma0:2: Allocation of TX ring 0x200 failed
[ 1.121215] bgmac_bcma bcma0:2: Unable to alloc memory for DMA
[ 1.127626] bgmac_bcma: probe of bcma0:2 failed with error -12
[ 1.133838] bgmac_bcma: Broadcom 47xx GBit MAC driver loaded
This change fixes above regression in addition to the MIPS bcm47xx
commit 321c46b91550 ("MIPS: BCM47XX: Setup struct device for the SoC").
It also fixes another *old* GPIO regression caused by a parent pointing
to the NULL:
[ 0.157054] missing gpiochip .dev parent pointer
[ 0.157287] bcma: bus0: Error registering GPIO driver: -22
introduced by the commit 74f4e0cc6108 ("bcma: switch GPIO portions to
use GPIOLIB_IRQCHIP").
Fixes: f8c55dc6e828 ("MIPS: use generic dma noncoherent ops for simple noncoherent platforms")
Fixes: 74f4e0cc6108 ("bcma: switch GPIO portions to use GPIOLIB_IRQCHIP")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-mips@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
---
Christoph,
I don't know if this is what you had in mind. I am also not sure if we
should have the bcma_bus_type implement .dma_configure and set it to
platform_dma_configure?
drivers/bcma/host_soc.c | 2 ++
drivers/bcma/main.c | 2 ++
2 files changed, 4 insertions(+)
diff --git a/drivers/bcma/host_soc.c b/drivers/bcma/host_soc.c
index 90d5bdc12e03..fd2e8ff17c76 100644
--- a/drivers/bcma/host_soc.c
+++ b/drivers/bcma/host_soc.c
@@ -191,6 +191,8 @@ int __init bcma_host_soc_init(struct bcma_soc *soc)
struct bcma_bus *bus = &soc->bus;
int err;
+ bus->dev = soc->dev;
+
/* Scan bus and initialize it */
err = bcma_bus_early_register(bus);
if (err)
diff --git a/drivers/bcma/main.c b/drivers/bcma/main.c
index 8e7ca3e4c8c4..6793c2ff60fd 100644
--- a/drivers/bcma/main.c
+++ b/drivers/bcma/main.c
@@ -253,6 +253,8 @@ void bcma_prepare_core(struct bcma_bus *bus, struct bcma_device *core)
if (IS_ENABLED(CONFIG_OF) && bus->dev) {
core->dma_dev = bus->dev;
} else {
+ if (!core->dev.coherent_dma_mask)
+ core->dev.coherent_dma_mask = DMA_BIT_MASK(32);
core->dev.dma_mask = &core->dev.coherent_dma_mask;
core->dma_dev = &core->dev;
}
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] bcma: get SoC device struct & assign dma_mask
2022-01-07 4:17 [PATCH] bcma: get SoC device struct & assign dma_mask Florian Fainelli
@ 2022-01-10 9:09 ` Christoph Hellwig
2022-01-10 9:20 ` Rafał Miłecki
2022-01-10 18:13 ` Florian Fainelli
0 siblings, 2 replies; 4+ messages in thread
From: Christoph Hellwig @ 2022-01-10 9:09 UTC (permalink / raw)
To: Florian Fainelli
Cc: linux-mips, Rafał Miłecki, Christoph Hellwig, Linus Walleij
On Thu, Jan 06, 2022 at 08:17:44PM -0800, Florian Fainelli wrote:
> From: Rafał Miłecki <rafal@milecki.pl>
>
> For bus devices to be fully usable it's required to set their DMA
> parameters.
>
> For years it has been missing and remained unnoticed because of
> mips_dma_alloc_coherent() silently handling the empty coherent_dma_mask.
> Kernel 4.19 came with a lot of DMA changes and caused a regression on
> the bcm47xx. Starting with the commit f8c55dc6e828 ("MIPS: use generic
> dma noncoherent ops for simple noncoherent platforms") DMA coherent
> allocations just fail. Example:
> [ 1.114914] bgmac_bcma bcma0:2: Allocation of TX ring 0x200 failed
> [ 1.121215] bgmac_bcma bcma0:2: Unable to alloc memory for DMA
> [ 1.127626] bgmac_bcma: probe of bcma0:2 failed with error -12
> [ 1.133838] bgmac_bcma: Broadcom 47xx GBit MAC driver loaded
>
> This change fixes above regression in addition to the MIPS bcm47xx
> commit 321c46b91550 ("MIPS: BCM47XX: Setup struct device for the SoC").
How did it take so long to notice this?
> I don't know if this is what you had in mind. I am also not sure if we
> should have the bcma_bus_type implement .dma_configure and set it to
> platform_dma_configure?
Unless you have an OF tree that declares DMA limitations there is no
need to call platform_dma_configure.
> --- a/drivers/bcma/host_soc.c
> +++ b/drivers/bcma/host_soc.c
> @@ -191,6 +191,8 @@ int __init bcma_host_soc_init(struct bcma_soc *soc)
> struct bcma_bus *bus = &soc->bus;
> int err;
>
> + bus->dev = soc->dev;
> +
> /* Scan bus and initialize it */
> err = bcma_bus_early_register(bus);
> if (err)
> diff --git a/drivers/bcma/main.c b/drivers/bcma/main.c
> index 8e7ca3e4c8c4..6793c2ff60fd 100644
> --- a/drivers/bcma/main.c
> +++ b/drivers/bcma/main.c
> @@ -253,6 +253,8 @@ void bcma_prepare_core(struct bcma_bus *bus, struct bcma_device *core)
> if (IS_ENABLED(CONFIG_OF) && bus->dev) {
> core->dma_dev = bus->dev;
> } else {
> + if (!core->dev.coherent_dma_mask)
> + core->dev.coherent_dma_mask = DMA_BIT_MASK(32);
Is there any way coherent_dma_mask could already be set here?
> core->dev.dma_mask = &core->dev.coherent_dma_mask;
> core->dma_dev = &core->dev;
Not really needed for the quick fix, but pointing the dma_mask to the
coherent_dma_mask is a bad idea as it removes the often used feature
to use a different mask for the cohernent allocations vs the streaming
mappings.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] bcma: get SoC device struct & assign dma_mask
2022-01-10 9:09 ` Christoph Hellwig
@ 2022-01-10 9:20 ` Rafał Miłecki
2022-01-10 18:13 ` Florian Fainelli
1 sibling, 0 replies; 4+ messages in thread
From: Rafał Miłecki @ 2022-01-10 9:20 UTC (permalink / raw)
To: Christoph Hellwig, Florian Fainelli; +Cc: linux-mips, Linus Walleij
On 10.01.2022 10:09, Christoph Hellwig wrote:
> On Thu, Jan 06, 2022 at 08:17:44PM -0800, Florian Fainelli wrote:
>> From: Rafał Miłecki <rafal@milecki.pl>
>>
>> For bus devices to be fully usable it's required to set their DMA
>> parameters.
>>
>> For years it has been missing and remained unnoticed because of
>> mips_dma_alloc_coherent() silently handling the empty coherent_dma_mask.
>> Kernel 4.19 came with a lot of DMA changes and caused a regression on
>> the bcm47xx. Starting with the commit f8c55dc6e828 ("MIPS: use generic
>> dma noncoherent ops for simple noncoherent platforms") DMA coherent
>> allocations just fail. Example:
>> [ 1.114914] bgmac_bcma bcma0:2: Allocation of TX ring 0x200 failed
>> [ 1.121215] bgmac_bcma bcma0:2: Unable to alloc memory for DMA
>> [ 1.127626] bgmac_bcma: probe of bcma0:2 failed with error -12
>> [ 1.133838] bgmac_bcma: Broadcom 47xx GBit MAC driver loaded
>>
>> This change fixes above regression in addition to the MIPS bcm47xx
>> commit 321c46b91550 ("MIPS: BCM47XX: Setup struct device for the SoC").
>
> How did it take so long to notice this?
I noticed it 3 years ago and sent semi-fix that wasn't accepted (for
probably a good reason) back then:
[PATCH wireless-drivers-next] bcma: get SoC device struct & copy its DMA params to the subdevices
https://patchwork.kernel.org/project/linux-wireless/patch/20190121101121.24555-1-zajec5@gmail.com/
Since then OpenWrt carried on above fix as a downstream patch.
I guess OpenWrt is the only active user of that code.
Thanks a lot Florian for bringing that upstream.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] bcma: get SoC device struct & assign dma_mask
2022-01-10 9:09 ` Christoph Hellwig
2022-01-10 9:20 ` Rafał Miłecki
@ 2022-01-10 18:13 ` Florian Fainelli
1 sibling, 0 replies; 4+ messages in thread
From: Florian Fainelli @ 2022-01-10 18:13 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: linux-mips, Rafał Miłecki, Linus Walleij
On 1/10/22 1:09 AM, Christoph Hellwig wrote:
> On Thu, Jan 06, 2022 at 08:17:44PM -0800, Florian Fainelli wrote:
>> From: Rafał Miłecki <rafal@milecki.pl>
>>
>> For bus devices to be fully usable it's required to set their DMA
>> parameters.
>>
>> For years it has been missing and remained unnoticed because of
>> mips_dma_alloc_coherent() silently handling the empty coherent_dma_mask.
>> Kernel 4.19 came with a lot of DMA changes and caused a regression on
>> the bcm47xx. Starting with the commit f8c55dc6e828 ("MIPS: use generic
>> dma noncoherent ops for simple noncoherent platforms") DMA coherent
>> allocations just fail. Example:
>> [ 1.114914] bgmac_bcma bcma0:2: Allocation of TX ring 0x200 failed
>> [ 1.121215] bgmac_bcma bcma0:2: Unable to alloc memory for DMA
>> [ 1.127626] bgmac_bcma: probe of bcma0:2 failed with error -12
>> [ 1.133838] bgmac_bcma: Broadcom 47xx GBit MAC driver loaded
>>
>> This change fixes above regression in addition to the MIPS bcm47xx
>> commit 321c46b91550 ("MIPS: BCM47XX: Setup struct device for the SoC").
>
> How did it take so long to notice this?
>
>> I don't know if this is what you had in mind. I am also not sure if we
>> should have the bcma_bus_type implement .dma_configure and set it to
>> platform_dma_configure?
>
> Unless you have an OF tree that declares DMA limitations there is no
> need to call platform_dma_configure.
OK, so we may have to implement that callback then because on ARM-based
Devices we have BCMA plus Device Tree being used. Although none of those
ARM platforms define any DMA apertures or restrictions, I suppose
>
>> --- a/drivers/bcma/host_soc.c
>> +++ b/drivers/bcma/host_soc.c
>> @@ -191,6 +191,8 @@ int __init bcma_host_soc_init(struct bcma_soc *soc)
>> struct bcma_bus *bus = &soc->bus;
>> int err;
>>
>> + bus->dev = soc->dev;
>> +
>> /* Scan bus and initialize it */
>> err = bcma_bus_early_register(bus);
>> if (err)
>> diff --git a/drivers/bcma/main.c b/drivers/bcma/main.c
>> index 8e7ca3e4c8c4..6793c2ff60fd 100644
>> --- a/drivers/bcma/main.c
>> +++ b/drivers/bcma/main.c
>> @@ -253,6 +253,8 @@ void bcma_prepare_core(struct bcma_bus *bus, struct bcma_device *core)
>> if (IS_ENABLED(CONFIG_OF) && bus->dev) {
>> core->dma_dev = bus->dev;
>> } else {
>> + if (!core->dev.coherent_dma_mask)
>> + core->dev.coherent_dma_mask = DMA_BIT_MASK(32);
>
> Is there any way coherent_dma_mask could already be set here?
On MIPS-based devices (not using Device Tree), I don't see a way this
could be set, however on ARM based devices, since they use Device Tree,
maybe this value could be different than 0. I will run some tests on
both types of devices and post an updated patch if relevant.
Thanks!
>
>> core->dev.dma_mask = &core->dev.coherent_dma_mask;
>> core->dma_dev = &core->dev;
>
> Not really needed for the quick fix, but pointing the dma_mask to the
> coherent_dma_mask is a bad idea as it removes the often used feature
> to use a different mask for the cohernent allocations vs the streaming
> mappings.
OK.
--
Florian
^ permalink raw reply [flat|nested] 4+ messages in thread
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2022-01-07 4:17 [PATCH] bcma: get SoC device struct & assign dma_mask Florian Fainelli
2022-01-10 9:09 ` Christoph Hellwig
2022-01-10 9:20 ` Rafał Miłecki
2022-01-10 18:13 ` Florian Fainelli
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