* [PATCH 0/1] Add spi power control when set cs @ 2019-10-23 12:38 Luhua Xu 2019-10-23 12:38 ` [PATCH 1/1] spi: mediatek: add power control when set_cs Luhua Xu 2019-10-23 15:11 ` [PATCH 0/1] Add spi power control when set cs Mark Brown 0 siblings, 2 replies; 8+ messages in thread From: Luhua Xu @ 2019-10-23 12:38 UTC (permalink / raw) To: Mark Brown, Matthias Brugger Cc: wsd_upstream, linux-kernel, linux-spi, luhua.xu, linux-mediatek, linux-arm-kernel This patch add power control when set spi cs to fix register access violation. luhua.xu (1): spi: mediatek: add power control when set_cs drivers/spi/spi-mt65xx.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH 1/1] spi: mediatek: add power control when set_cs 2019-10-23 12:38 [PATCH 0/1] Add spi power control when set cs Luhua Xu @ 2019-10-23 12:38 ` Luhua Xu 2019-10-23 15:11 ` Mark Brown 2019-10-23 15:11 ` [PATCH 0/1] Add spi power control when set cs Mark Brown 1 sibling, 1 reply; 8+ messages in thread From: Luhua Xu @ 2019-10-23 12:38 UTC (permalink / raw) To: Mark Brown, Matthias Brugger Cc: wsd_upstream, linux-kernel, linux-spi, luhua.xu, linux-mediatek, linux-arm-kernel From: "luhua.xu" <luhua.xu@mediatek.com> Use runtime PM to power spi when set_cs As set_cs may be called from interrupt context, set runtime PM IRQ safe for spi. Signed-off-by: luhua.xu <luhua.xu@mediatek.com> --- drivers/spi/spi-mt65xx.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c index 6888a4d..039b67d 100644 --- a/drivers/spi/spi-mt65xx.c +++ b/drivers/spi/spi-mt65xx.c @@ -262,8 +262,16 @@ static int mtk_spi_prepare_message(struct spi_master *master, static void mtk_spi_set_cs(struct spi_device *spi, bool enable) { u32 reg_val; + int ret; struct mtk_spi *mdata = spi_master_get_devdata(spi->master); + ret = pm_runtime_get_sync(spi->master->dev.parent); + if (ret < 0) { + pm_runtime_put_noidle(spi->master->dev.parent); + dev_err(&spi->dev, "failed to power device(%d)\n", ret); + return; + } + reg_val = readl(mdata->base + SPI_CMD_REG); if (!enable) { reg_val |= SPI_CMD_PAUSE_EN; @@ -274,6 +282,9 @@ static void mtk_spi_set_cs(struct spi_device *spi, bool enable) mdata->state = MTK_SPI_IDLE; mtk_spi_reset(mdata); } + + pm_runtime_mark_last_busy(spi->master->dev.parent); + pm_runtime_put_autosuspend(spi->master->dev.parent); } static void mtk_spi_prepare_transfer(struct spi_master *master, @@ -749,6 +760,7 @@ static int mtk_spi_probe(struct platform_device *pdev) clk_disable_unprepare(mdata->spi_clk); pm_runtime_enable(&pdev->dev); + pm_runtime_irq_safe(&pdev->dev); ret = devm_spi_register_master(&pdev->dev, master); if (ret) { -- 2.6.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] spi: mediatek: add power control when set_cs 2019-10-23 12:38 ` [PATCH 1/1] spi: mediatek: add power control when set_cs Luhua Xu @ 2019-10-23 15:11 ` Mark Brown 2019-10-24 6:25 ` luhua xu 0 siblings, 1 reply; 8+ messages in thread From: Mark Brown @ 2019-10-23 15:11 UTC (permalink / raw) To: Luhua Xu Cc: wsd_upstream, linux-kernel, linux-spi, linux-mediatek, Matthias Brugger, linux-arm-kernel [-- Attachment #1.1: Type: text/plain, Size: 491 bytes --] On Wed, Oct 23, 2019 at 08:38:42AM -0400, Luhua Xu wrote: > From: "luhua.xu" <luhua.xu@mediatek.com> > Use runtime PM to power spi when set_cs > As set_cs may be called from interrupt context, > set runtime PM IRQ safe for spi. Why might we be trying to set the chip select state while the device is runtime idle? It seems like whatever is trying to set the chip select should be dealing with this, not the chip select operation itself since that's unlikely to be happening in isolation. [-- Attachment #1.2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] [-- Attachment #2: Type: text/plain, Size: 176 bytes --] _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] spi: mediatek: add power control when set_cs 2019-10-23 15:11 ` Mark Brown @ 2019-10-24 6:25 ` luhua xu 2019-10-24 10:11 ` luhua xu 2019-10-24 10:23 ` Mark Brown 0 siblings, 2 replies; 8+ messages in thread From: luhua xu @ 2019-10-24 6:25 UTC (permalink / raw) To: Mark Brown Cc: wsd_upstream, linux-kernel, linux-spi, linux-mediatek, Matthias Brugger, linux-arm-kernel On Wed, 2019-10-23 at 16:11 +0100, Mark Brown wrote: > On Wed, Oct 23, 2019 at 08:38:42AM -0400, Luhua Xu wrote: > > From: "luhua.xu" <luhua.xu@mediatek.com> > > > Use runtime PM to power spi when set_cs > > As set_cs may be called from interrupt context, > > set runtime PM IRQ safe for spi. > > Why might we be trying to set the chip select state while the device is > runtime idle? It seems like whatever is trying to set the chip select > should be dealing with this, not the chip select operation itself since > that's unlikely to be happening in isolation. Hi Mark, Spi framework provideds spi_setup() to modify spi settings for spi device (maybe spi is runtime idle now), and this will call spi_controller->set_cs() accessing registers. Other spi_controller callbacks that need to access hardware registers, are triggered by spi transfer. Spi framework will get and put runtime power in __spi_pump_message(). _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] spi: mediatek: add power control when set_cs 2019-10-24 6:25 ` luhua xu @ 2019-10-24 10:11 ` luhua xu 2019-10-24 11:19 ` Mark Brown 2019-10-24 10:23 ` Mark Brown 1 sibling, 1 reply; 8+ messages in thread From: luhua xu @ 2019-10-24 10:11 UTC (permalink / raw) To: Mark Brown Cc: wsd_upstream, linux-kernel, linux-spi, linux-mediatek, Matthias Brugger, luhua.xu, linux-arm-kernel On Thu, 2019-10-24 at 14:25 +0800, luhua xu wrote: > On Wed, 2019-10-23 at 16:11 +0100, Mark Brown wrote: > > On Wed, Oct 23, 2019 at 08:38:42AM -0400, Luhua Xu wrote: > > > From: "luhua.xu" <luhua.xu@mediatek.com> > > > > > Use runtime PM to power spi when set_cs > > > As set_cs may be called from interrupt context, > > > set runtime PM IRQ safe for spi. > > > > Why might we be trying to set the chip select state while the device is > > runtime idle? It seems like whatever is trying to set the chip select > > should be dealing with this, not the chip select operation itself since > > that's unlikely to be happening in isolation. > > Hi Mark, > Spi framework provideds spi_setup() to modify spi settings for spi > device (maybe spi is runtime idle now), and this will call > spi_controller->set_cs() accessing registers. > Other spi_controller callbacks that need to access hardware registers, > are triggered by spi transfer. Spi framework will get and put runtime > power in __spi_pump_message(). hi Mark, If the spi slaver who wants to set cs need to power spi itself , this means we need to provide spi power on/off APIs while spi controller is runtime PM device. And spi slaver needs to power spi itself when it wants to set cs, and don't need to do so when do spi data transfer. I see several case of spi driver with power control: (1)No clk control in set_cs, such as spi-cadence.c (2)Enable spi clk in probe before the first time hitting reg, and never power down. Such as spi-sifive.c spi-armada-3700.c (3)Enable spi clk in controller->set_cs callback, such as spi-geni-qcom.c. My patch works the same as (3).For mtk platform, without this patch, if user do spi_setup(), cs setting cannot take effect, and reg access violation occurs. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] spi: mediatek: add power control when set_cs 2019-10-24 10:11 ` luhua xu @ 2019-10-24 11:19 ` Mark Brown 0 siblings, 0 replies; 8+ messages in thread From: Mark Brown @ 2019-10-24 11:19 UTC (permalink / raw) To: luhua xu Cc: wsd_upstream, linux-kernel, linux-spi, linux-mediatek, Matthias Brugger, linux-arm-kernel [-- Attachment #1.1: Type: text/plain, Size: 423 bytes --] On Thu, Oct 24, 2019 at 06:11:20PM +0800, luhua xu wrote: > (3)Enable spi clk in controller->set_cs callback, such as > spi-geni-qcom.c. > My patch works the same as (3).For mtk platform, without this > patch, if user do spi_setup(), cs setting cannot take effect, and reg > access violation occurs. Other drivers having problems isn't a good reason to introduce more drivers with problems. [-- Attachment #1.2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] [-- Attachment #2: Type: text/plain, Size: 176 bytes --] _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] spi: mediatek: add power control when set_cs 2019-10-24 6:25 ` luhua xu 2019-10-24 10:11 ` luhua xu @ 2019-10-24 10:23 ` Mark Brown 1 sibling, 0 replies; 8+ messages in thread From: Mark Brown @ 2019-10-24 10:23 UTC (permalink / raw) To: luhua xu Cc: wsd_upstream, linux-kernel, linux-spi, linux-mediatek, Matthias Brugger, linux-arm-kernel [-- Attachment #1.1: Type: text/plain, Size: 304 bytes --] On Thu, Oct 24, 2019 at 02:25:19PM +0800, luhua xu wrote: > Spi framework provideds spi_setup() to modify spi settings for spi > device (maybe spi is runtime idle now), and this will call > spi_controller->set_cs() accessing registers. OK, so fix that so it takes the power at the setup() level then. [-- Attachment #1.2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] [-- Attachment #2: Type: text/plain, Size: 176 bytes --] _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 0/1] Add spi power control when set cs 2019-10-23 12:38 [PATCH 0/1] Add spi power control when set cs Luhua Xu 2019-10-23 12:38 ` [PATCH 1/1] spi: mediatek: add power control when set_cs Luhua Xu @ 2019-10-23 15:11 ` Mark Brown 1 sibling, 0 replies; 8+ messages in thread From: Mark Brown @ 2019-10-23 15:11 UTC (permalink / raw) To: Luhua Xu Cc: wsd_upstream, linux-kernel, linux-spi, linux-mediatek, Matthias Brugger, linux-arm-kernel [-- Attachment #1.1: Type: text/plain, Size: 450 bytes --] On Wed, Oct 23, 2019 at 08:38:41AM -0400, Luhua Xu wrote: > This patch add power control when set spi cs to fix register > access violation. Please don't send cover letters for single patches, if there is anything that needs saying put it in the changelog of the patch or after the --- if it's administrative stuff. This reduces mail volume and ensures that any important information is recorded in the changelog rather than being lost. [-- Attachment #1.2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] [-- Attachment #2: Type: text/plain, Size: 176 bytes --] _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2019-10-24 11:19 UTC | newest] Thread overview: 8+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2019-10-23 12:38 [PATCH 0/1] Add spi power control when set cs Luhua Xu 2019-10-23 12:38 ` [PATCH 1/1] spi: mediatek: add power control when set_cs Luhua Xu 2019-10-23 15:11 ` Mark Brown 2019-10-24 6:25 ` luhua xu 2019-10-24 10:11 ` luhua xu 2019-10-24 11:19 ` Mark Brown 2019-10-24 10:23 ` Mark Brown 2019-10-23 15:11 ` [PATCH 0/1] Add spi power control when set cs Mark Brown
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