> -----Original Message-----
> From: Vivi, Rodrigo <rodrigo.vivi@xxxxxxxxx>
> Sent: Monday, October 28, 2024 8:27 PM
> To: Usyskin, Alexander <alexander.usyskin@xxxxxxxxx>; Gupta, Anshuman
> <anshuman.gupta@xxxxxxxxx>; Deak, Imre <imre.deak@xxxxxxxxx>
> Cc: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>; Richard Weinberger
> <richard@xxxxxx>; Vignesh Raghavendra <vigneshr@xxxxxx>; De Marchi,
> Lucas <lucas.demarchi@xxxxxxxxx>; Thomas Hellström
> <thomas.hellstrom@xxxxxxxxxxxxxxx>; Maarten Lankhorst
> <maarten.lankhorst@xxxxxxxxxxxxxxx>; Maxime Ripard <mripard@xxxxxxxxxx>;
> Thomas Zimmermann <tzimmermann@xxxxxxx>; David Airlie
> <airlied@xxxxxxxxx>; Simona Vetter <simona@xxxxxxxx>; Jani Nikula
> <jani.nikula@xxxxxxxxxxxxxxx>; Joonas Lahtinen
> <joonas.lahtinen@xxxxxxxxxxxxxxx>; Tvrtko Ursulin <tursulin@xxxxxxxxxxx>;
> Weil, Oren jer <oren.jer.weil@xxxxxxxxx>; linux-mtd@xxxxxxxxxxxxxxxxxxx; dri-
> devel@xxxxxxxxxxxxxxxxxxxxx; intel-gfx@xxxxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH 06/10] mtd: intel-dg: wake card on operations
>
> On Tue, Oct 22, 2024 at 01:41:15PM +0300, Alexander Usyskin wrote:
> > Enable runtime PM in mtd driver to notify graphics driver that whole
> > card should be kept awake while nvm operations are performed through
> > this driver.
> >
> > CC: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
> > Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
> > ---
> > drivers/mtd/devices/mtd-intel-dg.c | 73
> > +++++++++++++++++++++++++-----
> > 1 file changed, 61 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/mtd/devices/mtd-intel-dg.c
> > b/drivers/mtd/devices/mtd-intel-dg.c
> > index 4951438e8faf..3d53f35478e8 100644
> > --- a/drivers/mtd/devices/mtd-intel-dg.c
> > +++ b/drivers/mtd/devices/mtd-intel-dg.c
> > @@ -15,11 +15,14 @@
> > #include <linux/module.h>
> > #include <linux/mtd/mtd.h>
> > #include <linux/mtd/partitions.h>
> > +#include <linux/pm_runtime.h>
> > #include <linux/string.h>
> > #include <linux/slab.h>
> > #include <linux/sizes.h>
> > #include <linux/types.h>
> >
> > +#define INTEL_DG_NVM_RPM_TIMEOUT 500
> > +
> > struct intel_dg_nvm {
> > struct kref refcnt;
> > struct mtd_info mtd;
> > @@ -462,6 +465,7 @@ static int intel_dg_mtd_erase(struct mtd_info *mtd,
> struct erase_info *info)
> > loff_t from;
> > size_t len;
> > size_t total_len;
> > + int ret = 0;
> >
> > if (WARN_ON(!nvm))
> > return -EINVAL;
> > @@ -476,20 +480,28 @@ static int intel_dg_mtd_erase(struct mtd_info
> *mtd, struct erase_info *info)
> > total_len = info->len;
> > addr = info->addr;
> >
> > + ret = pm_runtime_resume_and_get(mtd->dev.parent);
> > + if (ret < 0) {
> > + dev_err(&mtd->dev, "rpm: get failed %d\n", ret);
> > + return ret;
> > + }
> > +
> > guard(mutex)(&nvm->lock);
> >
> > while (total_len > 0) {
> > if (!IS_ALIGNED(addr, SZ_4K) || !IS_ALIGNED(total_len,
> SZ_4K)) {
> > dev_err(&mtd->dev, "unaligned erase %llx %zx\n",
> addr, total_len);
> > info->fail_addr = addr;
> > - return -ERANGE;
> > + ret = -ERANGE;
> > + goto out;
> > }
> >
> > idx = idg_nvm_get_region(nvm, addr);
> > if (idx >= nvm->nregions) {
> > dev_err(&mtd->dev, "out of range");
> > info->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
> > - return -ERANGE;
> > + ret = -ERANGE;
> > + goto out;
> > }
> >
> > from = addr - nvm->regions[idx].offset; @@ -505,14 +517,18
> @@
> > static int intel_dg_mtd_erase(struct mtd_info *mtd, struct erase_info *info)
> > if (bytes < 0) {
> > dev_dbg(&mtd->dev, "erase failed with %zd\n",
> bytes);
> > info->fail_addr += nvm->regions[idx].offset;
> > - return bytes;
> > + ret = bytes;
> > + goto out;
> > }
> >
> > addr += len;
> > total_len -= len;
> > }
> >
> > - return 0;
> > +out:
> > + pm_runtime_mark_last_busy(mtd->dev.parent);
> > + pm_runtime_put_autosuspend(mtd->dev.parent);
> > + return ret;
> > }
> >
> > static int intel_dg_mtd_read(struct mtd_info *mtd, loff_t from,
> > size_t len, @@ -541,17 +557,25 @@ static int intel_dg_mtd_read(struct
> mtd_info *mtd, loff_t from, size_t len,
> > if (len > nvm->regions[idx].size - from)
> > len = nvm->regions[idx].size - from;
> >
> > + ret = pm_runtime_resume_and_get(mtd->dev.parent);
> > + if (ret < 0) {
> > + dev_err(&mtd->dev, "rpm: get failed %zd\n", ret);
> > + return ret;
> > + }
> > +
> > guard(mutex)(&nvm->lock);
> >
> > ret = idg_read(nvm, region, from, len, buf);
> > if (ret < 0) {
> > dev_dbg(&mtd->dev, "read failed with %zd\n", ret);
> > - return ret;
> > + } else {
> > + *retlen = ret;
> > + ret = 0;
> > }
> >
> > - *retlen = ret;
> > -
> > - return 0;
> > + pm_runtime_mark_last_busy(mtd->dev.parent);
> > + pm_runtime_put_autosuspend(mtd->dev.parent);
> > + return ret;
> > }
> >
> > static int intel_dg_mtd_write(struct mtd_info *mtd, loff_t to, size_t
> > len, @@ -580,17 +604,25 @@ static int intel_dg_mtd_write(struct mtd_info
> *mtd, loff_t to, size_t len,
> > if (len > nvm->regions[idx].size - to)
> > len = nvm->regions[idx].size - to;
> >
> > + ret = pm_runtime_resume_and_get(mtd->dev.parent);
> > + if (ret < 0) {
> > + dev_err(&mtd->dev, "rpm: get failed %zd\n", ret);
> > + return ret;
> > + }
> > +
> > guard(mutex)(&nvm->lock);
> >
> > ret = idg_write(nvm, region, to, len, buf);
> > if (ret < 0) {
> > dev_dbg(&mtd->dev, "write failed with %zd\n", ret);
> > - return ret;
> > + } else {
> > + *retlen = ret;
> > + ret = 0;
> > }
> >
> > - *retlen = ret;
> > -
> > - return 0;
> > + pm_runtime_mark_last_busy(mtd->dev.parent);
> > + pm_runtime_put_autosuspend(mtd->dev.parent);
> > + return ret;
> > }
> >
> > static void intel_dg_nvm_release(struct kref *kref) @@ -722,6 +754,17
> > @@ static int intel_dg_mtd_probe(struct auxiliary_device *aux_dev,
> > n++;
> > }
> >
> > + pm_runtime_enable(device);
> > +
> > + pm_runtime_set_autosuspend_delay(device,
> INTEL_DG_NVM_RPM_TIMEOUT);
> > + pm_runtime_use_autosuspend(device);
>
> something looks strange here...
> on the functions above you get and put references for the parent device
> directly.
> But here you enable the rpm for this device.
>
> If I remember correctly from some old experiments, the rpm is smart enough
> and wake up the parent before waking up the child. So I'm wondering if we
> should only do the child without the parent.
Agree parent can't runtime suspend ind if it has active child.
Let this driver have it's own get/put routine instead of parent.
Thanks,
Anshuman Gupta.
>
> Cc: Imre Deak <imre.deak@xxxxxxxxx>
> Cc: Anshuman Gupta <anshuman.gupta@xxxxxxxxx>
>
> > +
> > + ret = pm_runtime_resume_and_get(device);
> > + if (ret < 0) {
> > + dev_err(device, "rpm: get failed %d\n", ret);
> > + goto err_norpm;
> > + }
> > +
> > nvm->base = devm_ioremap_resource(device, &invm->bar);
> > if (IS_ERR(nvm->base)) {
> > dev_err(device, "mmio not mapped\n"); @@ -744,9 +787,13
> @@ static
> > int intel_dg_mtd_probe(struct auxiliary_device *aux_dev,
> >
> > dev_set_drvdata(&aux_dev->dev, nvm);
> >
> > + pm_runtime_put(device);
> > return 0;
> >
> > err:
> > + pm_runtime_put(device);
> > +err_norpm:
> > + pm_runtime_disable(device);
> > kref_put(&nvm->refcnt, intel_dg_nvm_release);
> > return ret;
> > }
> > @@ -758,6 +805,8 @@ static void intel_dg_mtd_remove(struct
> auxiliary_device *aux_dev)
> > if (!nvm)
> > return;
> >
> > + pm_runtime_disable(&aux_dev->dev);
> > +
> > mtd_device_unregister(&nvm->mtd);
> >
> > dev_set_drvdata(&aux_dev->dev, NULL);
> > --
> > 2.43.0
> >
