* [PATCH] mmc: bcm2835: Use dma_request_chan() instead dma_request_slave_channel()
@ 2019-12-17 11:26 Peter Ujfalusi
2019-12-17 11:37 ` Nicolas Saenz Julienne
0 siblings, 1 reply; 3+ messages in thread
From: Peter Ujfalusi @ 2019-12-17 11:26 UTC (permalink / raw)
To: ulf.hansson, f.fainelli, rjui, sbranden, nsaenzjulienne
Cc: vkoul, linux-mmc, linux-kernel, bcm-kernel-feedback-list,
linux-rpi-kernel, linux-arm-kernel
dma_request_slave_channel() is a wrapper on top of dma_request_chan()
eating up the error code.
By using dma_request_chan() directly the driver can support deferred
probing against DMA.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
drivers/mmc/host/bcm2835.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
index 99f61fd2a658..3821f159d36d 100644
--- a/drivers/mmc/host/bcm2835.c
+++ b/drivers/mmc/host/bcm2835.c
@@ -1393,7 +1393,15 @@ static int bcm2835_probe(struct platform_device *pdev)
host->dma_chan = NULL;
host->dma_desc = NULL;
- host->dma_chan_rxtx = dma_request_slave_channel(dev, "rx-tx");
+ host->dma_chan_rxtx = dma_request_chan(dev, "rx-tx");
+ if (IS_ERR(host->dma_chan_rxtx)) {
+ if (PTR_ERR(host->dma_chan_rxtx) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+
+ /* Ignore errors to fall back to PIO mode */
+ host->dma_chan_rxtx = NULL;
+ }
+
clk = devm_clk_get(dev, NULL);
if (IS_ERR(clk)) {
--
Peter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] mmc: bcm2835: Use dma_request_chan() instead dma_request_slave_channel()
2019-12-17 11:26 [PATCH] mmc: bcm2835: Use dma_request_chan() instead dma_request_slave_channel() Peter Ujfalusi
@ 2019-12-17 11:37 ` Nicolas Saenz Julienne
2019-12-17 12:15 ` Peter Ujfalusi
0 siblings, 1 reply; 3+ messages in thread
From: Nicolas Saenz Julienne @ 2019-12-17 11:37 UTC (permalink / raw)
To: Peter Ujfalusi, ulf.hansson, f.fainelli, rjui, sbranden
Cc: vkoul, linux-mmc, linux-kernel, bcm-kernel-feedback-list,
linux-rpi-kernel, linux-arm-kernel
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Hi Peter,
On Tue, 2019-12-17 at 13:26 +0200, Peter Ujfalusi wrote:
> dma_request_slave_channel() is a wrapper on top of dma_request_chan()
> eating up the error code.
>
> By using dma_request_chan() directly the driver can support deferred
> probing against DMA.
>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
> ---
> drivers/mmc/host/bcm2835.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
> index 99f61fd2a658..3821f159d36d 100644
> --- a/drivers/mmc/host/bcm2835.c
> +++ b/drivers/mmc/host/bcm2835.c
> @@ -1393,7 +1393,15 @@ static int bcm2835_probe(struct platform_device *pdev)
> host->dma_chan = NULL;
> host->dma_desc = NULL;
>
> - host->dma_chan_rxtx = dma_request_slave_channel(dev, "rx-tx");
> + host->dma_chan_rxtx = dma_request_chan(dev, "rx-tx");
> + if (IS_ERR(host->dma_chan_rxtx)) {
> + if (PTR_ERR(host->dma_chan_rxtx) == -EPROBE_DEFER)
> + return -EPROBE_DEFER;
I think you should 'goto err' here, as you have to free the mmc host structure
allocated earlier in the probe function.
Other than that the patch looks good to me.
Regards,
Nicolas
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^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] mmc: bcm2835: Use dma_request_chan() instead dma_request_slave_channel()
2019-12-17 11:37 ` Nicolas Saenz Julienne
@ 2019-12-17 12:15 ` Peter Ujfalusi
0 siblings, 0 replies; 3+ messages in thread
From: Peter Ujfalusi @ 2019-12-17 12:15 UTC (permalink / raw)
To: Nicolas Saenz Julienne, ulf.hansson, f.fainelli, rjui, sbranden
Cc: vkoul, linux-mmc, linux-kernel, bcm-kernel-feedback-list,
linux-rpi-kernel, linux-arm-kernel
On 17/12/2019 13.37, Nicolas Saenz Julienne wrote:
> Hi Peter,
>
> On Tue, 2019-12-17 at 13:26 +0200, Peter Ujfalusi wrote:
>> dma_request_slave_channel() is a wrapper on top of dma_request_chan()
>> eating up the error code.
>>
>> By using dma_request_chan() directly the driver can support deferred
>> probing against DMA.
>>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
>> ---
>> drivers/mmc/host/bcm2835.c | 10 +++++++++-
>> 1 file changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
>> index 99f61fd2a658..3821f159d36d 100644
>> --- a/drivers/mmc/host/bcm2835.c
>> +++ b/drivers/mmc/host/bcm2835.c
>> @@ -1393,7 +1393,15 @@ static int bcm2835_probe(struct platform_device *pdev)
>> host->dma_chan = NULL;
>> host->dma_desc = NULL;
>>
>> - host->dma_chan_rxtx = dma_request_slave_channel(dev, "rx-tx");
>> + host->dma_chan_rxtx = dma_request_chan(dev, "rx-tx");
>> + if (IS_ERR(host->dma_chan_rxtx)) {
>> + if (PTR_ERR(host->dma_chan_rxtx) == -EPROBE_DEFER)
>> + return -EPROBE_DEFER;
>
> I think you should 'goto err' here, as you have to free the mmc host structure
> allocated earlier in the probe function.
You are right.
> Other than that the patch looks good to me.
>
> Regards,
> Nicolas
>
- Péter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
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2019-12-17 11:26 [PATCH] mmc: bcm2835: Use dma_request_chan() instead dma_request_slave_channel() Peter Ujfalusi
2019-12-17 11:37 ` Nicolas Saenz Julienne
2019-12-17 12:15 ` Peter Ujfalusi
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