Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx> writes:
> As request by Grant Likely, there is no more cover letter. Full changelog is following.
> I am still reluctant to add this changelog in the patch description, as it adds no value to
> the patch itself: when it was needed I try to updat comments or patch description.
> I understand that Grant Likely would need an ack from other user as this patch fix a corner case.
> Kevin Hilman made a few comments on this patch so he could add his "Ack by" or at least his "Review by".
A couple more comments...
>
> Changelog:
> * Change from v1 to v2:
> Rebase on linus/master (after 2.6.37-rc1)
> Do some clean-up and fix indentation on both patches
> Add more explanations for patch 2
>
> * Change from v2 to v3:
> Use directly resume function of spi_master instead of using function
> from spi_device as Grant Likely pointed it out.
> Force this transition explicitly for each CS used by a device.
>
> * Change from v3 to v4:
> Patch clean-up according to Kevin Hilman and checkpatch.
> Now force CS to be in inactive state only if it was inactive when it was
> suspended.
>
> * Change from v4 to v5:
> Rebase on linus/master (after 2.6.37-rc3)
> Collapse some lines as pointed by Grant Likely
> Fix a spelling
>
>
> == CUT HERE ==
> When SPI wake up from OFF mode, CS is in the wrong state: force it to the inactive state.
>
> During the system life, I monitored the CS behavior using a oscilloscope.
> I also activated debug in omap2_mcspi, so I saw when driver disable the clocks and restore context when device is not used.
> Each time the CS was in the correct state.
> It was only when system was put suspend to ram with off-mode activated that on resume the CS was in wrong state( ie activated).
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/spi/omap2_mcspi.c | 33 +++++++++++++++++++++++++++++++++
> 1 files changed, 33 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
> index 2a651e6..dcc024a 100644
> --- a/drivers/spi/omap2_mcspi.c
> +++ b/drivers/spi/omap2_mcspi.c
> @@ -1305,11 +1305,44 @@ static int __exit omap2_mcspi_remove(struct platform_device *pdev)
> /* work with hotplug and coldplug */
> MODULE_ALIAS("platform:omap2_mcspi");
>
> +#ifdef CONFIG_PM
You should use CONFIG_SUSPEND here
> +/* When SPI wake up from off-mode, CS is in activate state. If it was in
> + * unactive state when driver was suspend, then force it to unactive state at
> + * wake up.
> + */
> +static int omap2_mcspi_resume(struct platform_device *pdev)
> +{
> + struct spi_master *master = dev_get_drvdata(&pdev->dev);
> + struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
> + struct omap2_mcspi_cs *cs;
> +
> + omap2_mcspi_enable_clocks(mcspi);
> + list_for_each_entry(cs, &omap2_mcspi_ctx[master->bus_num - 1].cs,
> + node) {
> + if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
> +
> + /* We need to toggle CS state for OMAP take this
> + * change in account.
> + */
> + MOD_REG_BIT(cs->chconf0, OMAP2_MCSPI_CHCONF_FORCE, 1);
> + __raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
> + MOD_REG_BIT(cs->chconf0, OMAP2_MCSPI_CHCONF_FORCE, 0);
> + __raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
> + }
> + }
> + omap2_mcspi_disable_clocks(mcspi);
> + return 0;
> +}
> +#else
> +#define omap2_mcspi_resume NULL
> +#endif
> +
> static struct platform_driver omap2_mcspi_driver = {
> .driver = {
> .name = "omap2_mcspi",
> .owner = THIS_MODULE,
> },
> + .resume = omap2_mcspi_resume,
This is adding legacy PM methods. Instead, you should add a struct
dev_pm_ops and add the resume method there.
Kevin
> .remove = __exit_p(omap2_mcspi_remove),
> };
> -- 1.7.0.4
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