* [PATCH] USB: usblp: reset device at probe for Fuji Xerox DocuPrint P475 AP
@ 2025-11-28 6:52 Miao Li
2025-12-17 13:27 ` Greg KH
0 siblings, 1 reply; 2+ messages in thread
From: Miao Li @ 2025-11-28 6:52 UTC (permalink / raw)
To: zaitcev, gregkh; +Cc: linux-usb, linux-kernel, limiao870622, Miao Li
From: Miao Li <limiao@kylinos.cn>
when connecting Fuji Xerox DocuPrint P475 AP printer(which vid:pid is
0550:020e) to Huawei hisi platform and do reboot test for 500 cycles,
usblp probe function executed successfully but there is a small
chance it might not work, we can reset the device at probe to deal
with the problem.
Signed-off-by: Miao Li <limiao@kylinos.cn>
---
drivers/usb/class/usblp.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index a7a1d38b6bef..566930eb88a1 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -210,6 +210,7 @@ struct quirk_printer_struct {
#define USBLP_QUIRK_BIDIR 0x1 /* reports bidir but requires unidirectional mode (no INs/reads) */
#define USBLP_QUIRK_USB_INIT 0x2 /* needs vendor USB init string */
#define USBLP_QUIRK_BAD_CLASS 0x4 /* descriptor uses vendor-specific Class or SubClass */
+#define USBLP_QUIRK_RESET_DEV 0x8 /* reset USB device */
static const struct quirk_printer_struct quirk_printers[] = {
{ 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
@@ -228,6 +229,7 @@ static const struct quirk_printer_struct quirk_printers[] = {
{ 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
{ 0x04f9, 0x000d, USBLP_QUIRK_BIDIR }, /* Brother Industries, Ltd HL-1440 Laser Printer */
{ 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
+ { 0x0550, 0x020e, USBLP_QUIRK_RESET_DEV }, /* FUJI XEROX DocuPrint P475 AP Printer */
{ 0, 0 }
};
@@ -1189,6 +1191,13 @@ static int usblp_probe(struct usb_interface *intf,
le16_to_cpu(dev->descriptor.idVendor),
le16_to_cpu(dev->descriptor.idProduct));
+ /*
+ * Some printer need to reset the device here or it might not work
+ * when finished probe.
+ */
+ if (usblp->quirks & USBLP_QUIRK_RESET_DEV)
+ usb_reset_device(dev);
+
/* Analyze and pick initial alternate settings and endpoints. */
protocol = usblp_select_alts(usblp);
if (protocol < 0) {
--
2.25.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] USB: usblp: reset device at probe for Fuji Xerox DocuPrint P475 AP
2025-11-28 6:52 [PATCH] USB: usblp: reset device at probe for Fuji Xerox DocuPrint P475 AP Miao Li
@ 2025-12-17 13:27 ` Greg KH
0 siblings, 0 replies; 2+ messages in thread
From: Greg KH @ 2025-12-17 13:27 UTC (permalink / raw)
To: Miao Li; +Cc: zaitcev, linux-usb, linux-kernel, Miao Li
On Fri, Nov 28, 2025 at 02:52:06PM +0800, Miao Li wrote:
> From: Miao Li <limiao@kylinos.cn>
>
> when connecting Fuji Xerox DocuPrint P475 AP printer(which vid:pid is
> 0550:020e) to Huawei hisi platform and do reboot test for 500 cycles,
> usblp probe function executed successfully but there is a small
> chance it might not work, we can reset the device at probe to deal
> with the problem.
>
> Signed-off-by: Miao Li <limiao@kylinos.cn>
> ---
> drivers/usb/class/usblp.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
> index a7a1d38b6bef..566930eb88a1 100644
> --- a/drivers/usb/class/usblp.c
> +++ b/drivers/usb/class/usblp.c
> @@ -210,6 +210,7 @@ struct quirk_printer_struct {
> #define USBLP_QUIRK_BIDIR 0x1 /* reports bidir but requires unidirectional mode (no INs/reads) */
> #define USBLP_QUIRK_USB_INIT 0x2 /* needs vendor USB init string */
> #define USBLP_QUIRK_BAD_CLASS 0x4 /* descriptor uses vendor-specific Class or SubClass */
> +#define USBLP_QUIRK_RESET_DEV 0x8 /* reset USB device */
>
> static const struct quirk_printer_struct quirk_printers[] = {
> { 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
> @@ -228,6 +229,7 @@ static const struct quirk_printer_struct quirk_printers[] = {
> { 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
> { 0x04f9, 0x000d, USBLP_QUIRK_BIDIR }, /* Brother Industries, Ltd HL-1440 Laser Printer */
> { 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
> + { 0x0550, 0x020e, USBLP_QUIRK_RESET_DEV }, /* FUJI XEROX DocuPrint P475 AP Printer */
> { 0, 0 }
> };
>
> @@ -1189,6 +1191,13 @@ static int usblp_probe(struct usb_interface *intf,
> le16_to_cpu(dev->descriptor.idVendor),
> le16_to_cpu(dev->descriptor.idProduct));
>
> + /*
> + * Some printer need to reset the device here or it might not work
> + * when finished probe.
> + */
> + if (usblp->quirks & USBLP_QUIRK_RESET_DEV)
> + usb_reset_device(dev);
This feels very very wrong. Why must a driver tell the device to reset
itself? How does it pass any Windows USB validation without such a
"reset"? Why does it require this?
Are you sure this isn't a bug in the host controller logic instead?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 2+ messages in thread
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2025-12-17 13:27 ` Greg KH
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