[PATCH] mtd: intel-dg: wake card on operations

Alexander Usyskin
2025-10-19T15:20:27Z

Enable runtime PM in mtd driver to notify parent graphics driver
that whole card should be kept awake while nvm operations are
performed through this driver.

CC: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
---
drivers/mtd/devices/mtd_intel_dg.c | 72 +++++++++++++++++++++++++-----
1 file changed, 60 insertions(+), 12 deletions(-)

diff --git a/drivers/mtd/devices/mtd_intel_dg.c b/drivers/mtd/devices/mtd_intel_dg.c
index b438ee5aacc3..9c8d1405219c 100644
--- a/drivers/mtd/devices/mtd_intel_dg.c
+++ b/drivers/mtd/devices/mtd_intel_dg.c
@@ -15,14 +15,18 @@
#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_MS 500
+
struct intel_dg_nvm {
struct kref refcnt;
struct mtd_info mtd;
+ struct device *dev;
struct mutex lock; /* region access lock */
void __iomem *base;
void __iomem *base2;
@@ -421,6 +425,8 @@ static int intel_dg_nvm_init(struct intel_dg_nvm *nvm, struct device *device,
unsigned int i, n;
int ret;

+ nvm->dev = device;
+
/* clean error register, previous errors are ignored */
idg_nvm_error(nvm);

@@ -494,6 +500,7 @@ static int intel_dg_mtd_erase(struct mtd_info *mtd, struct erase_info *info)
size_t total_len;
unsigned int idx;
ssize_t bytes;
+ int ret = 0;
loff_t from;
size_t len;
u8 region;
@@ -512,20 +519,28 @@ 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(nvm->dev);
+ 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;
+ break;
}

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;
+ break;
}

from = addr - nvm->regions[idx].offset;
@@ -541,14 +556,17 @@ 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;
+ break;
}

addr += len;
total_len -= len;
}

- return 0;
+ pm_runtime_mark_last_busy(nvm->dev);
+ pm_runtime_put_autosuspend(nvm->dev);
+ return ret;
}

static int intel_dg_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
@@ -577,17 +595,25 @@ 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(nvm->dev);
+ 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(nvm->dev);
+ pm_runtime_put_autosuspend(nvm->dev);
+ return ret;
}

static int intel_dg_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
@@ -616,17 +642,25 @@ 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(nvm->dev);
+ 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(nvm->dev);
+ pm_runtime_put_autosuspend(nvm->dev);
+ return ret;
}

static void intel_dg_nvm_release(struct kref *kref)
@@ -753,6 +787,17 @@ static int intel_dg_mtd_probe(struct auxiliary_device *aux_dev,
}
nvm->nregions = n; /* in case where kasprintf fail */

+ devm_pm_runtime_enable(device);
+
+ pm_runtime_set_autosuspend_delay(device, INTEL_DG_NVM_RPM_TIMEOUT_MS);
+ pm_runtime_use_autosuspend(device);
+
+ 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)) {
ret = PTR_ERR(nvm->base);
@@ -781,9 +826,12 @@ 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:
kref_put(&nvm->refcnt, intel_dg_nvm_release);
return ret;
}
--
2.43.0