| Message ID | df570fb6649da6bc3b5f2a68afcb5471e6148269.1499270277.git.digetx@gmail.com |
|---|---|
| State | Deferred |
| Headers | show |
On Wed, Jul 05, 2017 at 07:29:45PM +0300, Dmitry Osipenko wrote: > GART looses it's state only in case of a deepest suspend level. Let's not > waste memory if machine doesn't support that suspend level. > > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> > --- > drivers/iommu/tegra-gart.c | 36 +++++++++++++++++++++++++----------- > 1 file changed, 25 insertions(+), 11 deletions(-) I'm not sure about this. The savedata region uses 32 KiB of memory, which is really not a whole lot. In addition, the suspend mode can be set in different places during the boot process, some of which fairly late. I'm concerned that this boot order dependency is going to come back to bite us eventually. Thierry
On 26.09.2017 14:19, Thierry Reding wrote: > On Wed, Jul 05, 2017 at 07:29:45PM +0300, Dmitry Osipenko wrote: >> GART looses it's state only in case of a deepest suspend level. Let's not >> waste memory if machine doesn't support that suspend level. >> >> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> >> --- >> drivers/iommu/tegra-gart.c | 36 +++++++++++++++++++++++++----------- >> 1 file changed, 25 insertions(+), 11 deletions(-) > > I'm not sure about this. The savedata region uses 32 KiB of memory, > which is really not a whole lot. > > In addition, the suspend mode can be set in different places during the > boot process, some of which fairly late. I'm concerned that this boot > order dependency is going to come back to bite us eventually. > Indeed, suspend mode is set after drivers been probed, my bad. On the other hand LP0 support haven't been implemented for years, some of drivers do not implement suspend/resume. So maybe it's worth to give up on LP0 entirely...
diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c index 37e708fdbb5a..1557a6a9a438 100644 --- a/drivers/iommu/tegra-gart.c +++ b/drivers/iommu/tegra-gart.c @@ -31,6 +31,8 @@ #include <linux/iommu.h> #include <linux/of.h> +#include <soc/tegra/pmc.h> + #include <asm/cacheflush.h> /* bitmap of the page sizes currently supported */ @@ -354,10 +356,13 @@ static int tegra_gart_suspend(struct device *dev) u32 *data = gart->savedata; unsigned long flags; - spin_lock_irqsave(&gart->pte_lock, flags); - for_each_gart_pte(gart, iova) - *(data++) = gart_read_pte(gart, iova); - spin_unlock_irqrestore(&gart->pte_lock, flags); + if (gart->savedata != NULL) { + spin_lock_irqsave(&gart->pte_lock, flags); + for_each_gart_pte(gart, iova) + *(data++) = gart_read_pte(gart, iova); + spin_unlock_irqrestore(&gart->pte_lock, flags); + } + return 0; } @@ -366,9 +371,12 @@ static int tegra_gart_resume(struct device *dev) struct gart_device *gart = dev_get_drvdata(dev); unsigned long flags; - spin_lock_irqsave(&gart->pte_lock, flags); - do_gart_setup(gart, gart->savedata); - spin_unlock_irqrestore(&gart->pte_lock, flags); + if (gart->savedata != NULL) { + spin_lock_irqsave(&gart->pte_lock, flags); + do_gart_setup(gart, gart->savedata); + spin_unlock_irqrestore(&gart->pte_lock, flags); + } + return 0; } @@ -412,10 +420,16 @@ static int tegra_gart_probe(struct platform_device *pdev) gart->iovmm_base = (dma_addr_t)res_remap->start; gart->page_count = (resource_size(res_remap) >> GART_PAGE_SHIFT); - gart->savedata = vmalloc(sizeof(u32) * gart->page_count); - if (!gart->savedata) { - dev_err(dev, "failed to allocate context save area\n"); - return -ENOMEM; + /* + * The registers store/restore is required only in case of a + * deepest sleep state, do not waste memory if it's unnecessary. + */ + if (tegra_pmc_get_suspend_mode() == TEGRA_SUSPEND_LP0) { + gart->savedata = vmalloc(sizeof(u32) * gart->page_count); + if (!gart->savedata) { + dev_err(dev, "failed to allocate context save area\n"); + return -ENOMEM; + } } platform_set_drvdata(pdev, gart);
GART looses it's state only in case of a deepest suspend level. Let's not waste memory if machine doesn't support that suspend level. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> --- drivers/iommu/tegra-gart.c | 36 +++++++++++++++++++++++++----------- 1 file changed, 25 insertions(+), 11 deletions(-)