On 19/01/18 05:52, Vinod Koul wrote:
On Tue, Jan 16, 2018 at 07:02:33PM +0000, srinivas.kandagatla@xxxxxxxxxx wrote:
From: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
When BAM is remotely controlled it does not sound correct to control
its clk on Linux side. Make it optional, so that its not madatory
s/madatory/mandatory
Yep,
for remote controlled BAM instances.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
drivers/dma/qcom/bam_dma.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
index 03c4eb3fd314..78e488e8f96d 100644
--- a/drivers/dma/qcom/bam_dma.c
+++ b/drivers/dma/qcom/bam_dma.c
@@ -1180,13 +1180,14 @@ static int bam_dma_probe(struct platform_device *pdev)
"qcom,controlled-remotely");
bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
but you still do clk_get unconditionally?
Only reason to do this way is to not break existing users in the mainline.
remotely controlled BAM is already supported in upstream driver, there
are users of this who pass clk from device tree, If I make this
conditional then subsequent reads to the BAM registers for those
instances might crash the system.
This sounds wrong to control clk from linux for the dma controller which
is remotely controlled. These users should be transitioned to new
bindings once the new bindings endup in the mainline.
- if (IS_ERR(bdev->bamclk))
- return PTR_ERR(bdev->bamclk);
-
- ret = clk_prepare_enable(bdev->bamclk);
- if (ret) {
- dev_err(bdev->dev, "failed to prepare/enable clock\n");
- return ret;
+ if (IS_ERR(bdev->bamclk)) {
+ bdev->bamclk = NULL;
+ } else {
+ ret = clk_prepare_enable(bdev->bamclk);
+ if (ret) {
+ dev_err(bdev->dev, "failed to prepare/enable clock\n");
+ return ret;
+ }
wouldn't it be better to set that an instance is remote controlled and thus
not at all visible to Linux?
We already have a flag "controlled_remotely" for that in the driver.
thanks,
srini
}
ret = bam_init(bdev);
--
2.15.1
--
To unsubscribe from this list: send the line "unsubscribe dmaengine" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
