* [PATCH] spi: slink-tegra20: move runtime pm calls to transfer_one_message
@ 2013-03-08 6:21 Laxman Dewangan
[not found] ` <1362723679-1155-1-git-send-email-ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
0 siblings, 1 reply; 3+ messages in thread
From: Laxman Dewangan @ 2013-03-08 6:21 UTC (permalink / raw)
To: grant.likely-s3s/WqlpOiPyB63q8FvJNQ,
broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E
Cc: swarren-3lzwWm7+Weoh9ZMKESR00Q,
spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
linux-tegra-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA, Laxman Dewangan
The prepare_transfer_hardware() is called in atomic context and
calling synchronous runtime pm calls can create scheduling deadlock.
Therefore, in place of calling runtime PM calls from prepare/unprepare
message transfer, calling this in transfer_one_message().
Signed-off-by: Laxman Dewangan <ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
drivers/spi/spi-tegra20-slink.c | 25 ++++++++-----------------
1 files changed, 8 insertions(+), 17 deletions(-)
diff --git a/drivers/spi/spi-tegra20-slink.c b/drivers/spi/spi-tegra20-slink.c
index b8698b3..a829563 100644
--- a/drivers/spi/spi-tegra20-slink.c
+++ b/drivers/spi/spi-tegra20-slink.c
@@ -858,21 +858,6 @@ static int tegra_slink_setup(struct spi_device *spi)
return 0;
}
-static int tegra_slink_prepare_transfer(struct spi_master *master)
-{
- struct tegra_slink_data *tspi = spi_master_get_devdata(master);
-
- return pm_runtime_get_sync(tspi->dev);
-}
-
-static int tegra_slink_unprepare_transfer(struct spi_master *master)
-{
- struct tegra_slink_data *tspi = spi_master_get_devdata(master);
-
- pm_runtime_put(tspi->dev);
- return 0;
-}
-
static int tegra_slink_transfer_one_message(struct spi_master *master,
struct spi_message *msg)
{
@@ -885,6 +870,12 @@ static int tegra_slink_transfer_one_message(struct spi_master *master,
msg->status = 0;
msg->actual_length = 0;
+ ret = pm_runtime_get_sync(tspi->dev);
+ if (ret < 0) {
+ dev_err(tspi->dev, "runtime get failed: %d\n", ret);
+ goto done;
+ }
+
single_xfer = list_is_singular(&msg->transfers);
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
INIT_COMPLETION(tspi->xfer_completion);
@@ -921,6 +912,8 @@ static int tegra_slink_transfer_one_message(struct spi_master *master,
exit:
tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
tegra_slink_writel(tspi, tspi->def_command2_reg, SLINK_COMMAND2);
+ pm_runtime_put(tspi->dev);
+done:
msg->status = ret;
spi_finalize_current_message(master);
return ret;
@@ -1148,9 +1141,7 @@ static int tegra_slink_probe(struct platform_device *pdev)
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
master->setup = tegra_slink_setup;
- master->prepare_transfer_hardware = tegra_slink_prepare_transfer;
master->transfer_one_message = tegra_slink_transfer_one_message;
- master->unprepare_transfer_hardware = tegra_slink_unprepare_transfer;
master->num_chipselect = MAX_CHIP_SELECT;
master->bus_num = -1;
--
1.7.1.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] spi: slink-tegra20: move runtime pm calls to transfer_one_message
[not found] ` <1362723679-1155-1-git-send-email-ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
@ 2013-03-08 17:05 ` Stephen Warren
2013-03-12 19:07 ` Mark Brown
1 sibling, 0 replies; 3+ messages in thread
From: Stephen Warren @ 2013-03-08 17:05 UTC (permalink / raw)
To: Laxman Dewangan
Cc: grant.likely-s3s/WqlpOiPyB63q8FvJNQ,
broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E,
spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
linux-tegra-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA
On 03/07/2013 11:21 PM, Laxman Dewangan wrote:
> The prepare_transfer_hardware() is called in atomic context and
> calling synchronous runtime pm calls can create scheduling deadlock.
>
> Therefore, in place of calling runtime PM calls from prepare/unprepare
> message transfer, calling this in transfer_one_message().
Tested-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
This does fix some slightly intermittent lockups/crashes for me when
erasing and re-writing the SPI flash on Cardhu.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] spi: slink-tegra20: move runtime pm calls to transfer_one_message
[not found] ` <1362723679-1155-1-git-send-email-ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2013-03-08 17:05 ` Stephen Warren
@ 2013-03-12 19:07 ` Mark Brown
1 sibling, 0 replies; 3+ messages in thread
From: Mark Brown @ 2013-03-12 19:07 UTC (permalink / raw)
To: Laxman Dewangan
Cc: grant.likely-s3s/WqlpOiPyB63q8FvJNQ,
swarren-3lzwWm7+Weoh9ZMKESR00Q,
spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
linux-tegra-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA
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On Fri, Mar 08, 2013 at 11:51:19AM +0530, Laxman Dewangan wrote:
> The prepare_transfer_hardware() is called in atomic context and
> calling synchronous runtime pm calls can create scheduling deadlock.
Applied, thanks.
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^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-03-08 6:21 [PATCH] spi: slink-tegra20: move runtime pm calls to transfer_one_message Laxman Dewangan
[not found] ` <1362723679-1155-1-git-send-email-ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2013-03-08 17:05 ` Stephen Warren
2013-03-12 19:07 ` Mark Brown
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