When a card is present in the reader, the driver currently defers autosuspend by returning -EAGAIN during the suspend callback to trigger USB remote wakeup signaling. However, this does not guarantee that the mmc child device has been resumed, which may cause issues if it remains suspended while the card is accessible. This patch ensures that all child devices, including the mmc host controller, are explicitly resumed before returning -EAGAIN. This fixes a corner case introduced by earlier remote wakeup handling, improving reliability of runtime PM when a card is inserted.
Fixes: 883a87ddf2f1 ("misc: rtsx_usb: Use USB remote wakeup signaling for card insertion detection") Cc: stable@vger.kernel.org Signed-off-by: Ricky Wu ricky_wu@realtek.com --- drivers/misc/cardreader/rtsx_usb.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/misc/cardreader/rtsx_usb.c b/drivers/misc/cardreader/rtsx_usb.c index 148107a4547c..d007a4455ce5 100644 --- a/drivers/misc/cardreader/rtsx_usb.c +++ b/drivers/misc/cardreader/rtsx_usb.c @@ -698,6 +698,12 @@ static void rtsx_usb_disconnect(struct usb_interface *intf) }
#ifdef CONFIG_PM +static int rtsx_usb_resume_child(struct device *dev, void *data) +{ + pm_request_resume(dev); + return 0; +} + static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message) { struct rtsx_ucr *ucr = @@ -713,8 +719,10 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message) mutex_unlock(&ucr->dev_mutex);
/* Defer the autosuspend if card exists */ - if (val & (SD_CD | MS_CD)) + if (val & (SD_CD | MS_CD)) { + device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child); return -EAGAIN; + } } else { /* There is an ongoing operation*/ return -EAGAIN; @@ -724,12 +732,6 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message) return 0; }
-static int rtsx_usb_resume_child(struct device *dev, void *data) -{ - pm_request_resume(dev); - return 0; -} - static int rtsx_usb_resume(struct usb_interface *intf) { device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child);
+ Gavin
On Fri, 11 Jul 2025 at 16:02, Ricky Wu ricky_wu@realtek.com wrote:
When a card is present in the reader, the driver currently defers autosuspend by returning -EAGAIN during the suspend callback to trigger USB remote wakeup signaling. However, this does not guarantee that the mmc child device has been resumed, which may cause issues if it remains suspended while the card is accessible. This patch ensures that all child devices, including the mmc host controller, are explicitly resumed before returning -EAGAIN. This fixes a corner case introduced by earlier remote wakeup handling, improving reliability of runtime PM when a card is inserted.
Fixes: 883a87ddf2f1 ("misc: rtsx_usb: Use USB remote wakeup signaling for card insertion detection") Cc: stable@vger.kernel.org Signed-off-by: Ricky Wu ricky_wu@realtek.com
This seems reasonable to me, but perhaps some of the USB maintainers should have a closer look to see if this makes sense. Nevertheless, feel free to add:
Reviewed-by: Ulf Hansson ulf.hansson@linaro.org
Moreover, we had a related bug-report/fix posted for the rtsx_usb_sdmmc driver [1] not that long ago. Do you know if $subject patch solves this problem too? I have looped in Gavin, if he has some additional comments around this.
Kind regards Uffe
[1] https://lore.kernel.org/all/20250510031945.1004129-1-git@thegavinli.com/
drivers/misc/cardreader/rtsx_usb.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/misc/cardreader/rtsx_usb.c b/drivers/misc/cardreader/rtsx_usb.c index 148107a4547c..d007a4455ce5 100644 --- a/drivers/misc/cardreader/rtsx_usb.c +++ b/drivers/misc/cardreader/rtsx_usb.c @@ -698,6 +698,12 @@ static void rtsx_usb_disconnect(struct usb_interface *intf) }
#ifdef CONFIG_PM +static int rtsx_usb_resume_child(struct device *dev, void *data) +{
pm_request_resume(dev);return 0;+}
static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message) { struct rtsx_ucr *ucr = @@ -713,8 +719,10 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message) mutex_unlock(&ucr->dev_mutex);
/* Defer the autosuspend if card exists */
if (val & (SD_CD | MS_CD))
if (val & (SD_CD | MS_CD)) {device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child); return -EAGAIN;} } else { /* There is an ongoing operation*/ return -EAGAIN;@@ -724,12 +732,6 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message) return 0; }
-static int rtsx_usb_resume_child(struct device *dev, void *data) -{
pm_request_resume(dev);return 0;-}
static int rtsx_usb_resume(struct usb_interface *intf) { device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child); -- 2.25.1
I just tested out this patch, and it unfortunately does not address the issue I was running into (where the driver fails to detect inserting a SD card after the initial driver probe).
On Wed, Jul 16, 2025 at 6:39 AM Ulf Hansson ulf.hansson@linaro.org wrote:
- Gavin
On Fri, 11 Jul 2025 at 16:02, Ricky Wu ricky_wu@realtek.com wrote:
When a card is present in the reader, the driver currently defers autosuspend by returning -EAGAIN during the suspend callback to trigger USB remote wakeup signaling. However, this does not guarantee that the mmc child device has been resumed, which may cause issues if it remains suspended while the card is accessible. This patch ensures that all child devices, including the mmc host controller, are explicitly resumed before returning -EAGAIN. This fixes a corner case introduced by earlier remote wakeup handling, improving reliability of runtime PM when a card is inserted.
Fixes: 883a87ddf2f1 ("misc: rtsx_usb: Use USB remote wakeup signaling for card insertion detection") Cc: stable@vger.kernel.org Signed-off-by: Ricky Wu ricky_wu@realtek.com
This seems reasonable to me, but perhaps some of the USB maintainers should have a closer look to see if this makes sense. Nevertheless, feel free to add:
Reviewed-by: Ulf Hansson ulf.hansson@linaro.org
Moreover, we had a related bug-report/fix posted for the rtsx_usb_sdmmc driver [1] not that long ago. Do you know if $subject patch solves this problem too? I have looped in Gavin, if he has some additional comments around this.
Kind regards Uffe
[1] https://lore.kernel.org/all/20250510031945.1004129-1-git@thegavinli.com/
drivers/misc/cardreader/rtsx_usb.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/misc/cardreader/rtsx_usb.c b/drivers/misc/cardreader/rtsx_usb.c index 148107a4547c..d007a4455ce5 100644 --- a/drivers/misc/cardreader/rtsx_usb.c +++ b/drivers/misc/cardreader/rtsx_usb.c @@ -698,6 +698,12 @@ static void rtsx_usb_disconnect(struct usb_interface *intf) }
#ifdef CONFIG_PM +static int rtsx_usb_resume_child(struct device *dev, void *data) +{
pm_request_resume(dev);return 0;+}
static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message) { struct rtsx_ucr *ucr = @@ -713,8 +719,10 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message) mutex_unlock(&ucr->dev_mutex);
/* Defer the autosuspend if card exists */
if (val & (SD_CD | MS_CD))
if (val & (SD_CD | MS_CD)) {device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child); return -EAGAIN;} } else { /* There is an ongoing operation*/ return -EAGAIN;@@ -724,12 +732,6 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message) return 0; }
-static int rtsx_usb_resume_child(struct device *dev, void *data) -{
pm_request_resume(dev);return 0;-}
static int rtsx_usb_resume(struct usb_interface *intf) { device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child); -- 2.25.1
linux-stable-mirror@lists.linaro.org
-
Gavin Li -
Ricky Wu -
Ulf Hansson