* [U-Boot] [PATCH V2] [RFC] usb: storage: Limit transfer size to 120 kiB
@ 2019-09-17 14:43 Marek Vasut
2019-09-18 2:13 ` Bin Meng
0 siblings, 1 reply; 5+ messages in thread
From: Marek Vasut @ 2019-09-17 14:43 UTC (permalink / raw)
To: u-boot
Due to constant influx of more and more weird and broken USB sticks,
do as Linux does in commit 779b457f66e10de3471479373463b27fd308dc85
usb: storage: scsiglue: further describe our 240 sector limit
Just so we have some sort of documentation as to why
we limit our Mass Storage transfers to 240 sectors,
let's update the comment to make clearer that
devices were found that would choke with larger
transfers.
While at that, also make sure to clarify that other
operating systems have similar, albeit different,
limits on mass storage transfers.
And reduce the maximum transfer length of USB storage to 120 kiB.
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Simon Glass <sjg@chromium.org>
---
V2: Reshuffle the code a bit, always clamp the transfer size to 240 blocks
---
common/usb_storage.c | 43 ++++++++++++++++++++++---------------------
1 file changed, 22 insertions(+), 21 deletions(-)
diff --git a/common/usb_storage.c b/common/usb_storage.c
index 8c889bb1a6..e1b539a082 100644
--- a/common/usb_storage.c
+++ b/common/usb_storage.c
@@ -938,31 +938,32 @@ do_retry:
static void usb_stor_set_max_xfer_blk(struct usb_device *udev,
struct us_data *us)
{
- unsigned short blk;
- size_t __maybe_unused size;
- int __maybe_unused ret;
-
-#if !CONFIG_IS_ENABLED(DM_USB)
-#ifdef CONFIG_USB_EHCI_HCD
/*
- * The U-Boot EHCI driver can handle any transfer length as long as
- * there is enough free heap space left, but the SCSI READ(10) and
- * WRITE(10) commands are limited to 65535 blocks.
+ * Limit the total size of a transfer to 120 KB.
+ *
+ * Some devices are known to choke with anything larger. It seems like
+ * the problem stems from the fact that original IDE controllers had
+ * only an 8-bit register to hold the number of sectors in one transfer
+ * and even those couldn't handle a full 256 sectors.
+ *
+ * Because we want to make sure we interoperate with as many devices as
+ * possible, we will maintain a 240 sector transfer size limit for USB
+ * Mass Storage devices.
+ *
+ * Tests show that other operating have similar limits with Microsoft
+ * Windows 7 limiting transfers to 128 sectors for both USB2 and USB3
+ * and Apple Mac OS X 10.11 limiting transfers to 256 sectors for USB2
+ * and 2048 for USB3 devices.
*/
- blk = USHRT_MAX;
-#else
- blk = 20;
-#endif
-#else
+ unsigned short blk = 240;
+
+#if CONFIG_IS_ENABLED(DM_USB)
+ size_t size;
+ int ret;
+
ret = usb_get_max_xfer_size(udev, (size_t *)&size);
- if (ret < 0) {
- /* unimplemented, let's use default 20 */
- blk = 20;
- } else {
- if (size > USHRT_MAX * 512)
- size = USHRT_MAX * 512;
+ if ((ret >= 0) && (size < 240 * 512))
blk = size / 512;
- }
#endif
us->max_xfer_blk = blk;
--
2.23.0.rc1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [U-Boot] [PATCH V2] [RFC] usb: storage: Limit transfer size to 120 kiB
2019-09-17 14:43 [U-Boot] [PATCH V2] [RFC] usb: storage: Limit transfer size to 120 kiB Marek Vasut
@ 2019-09-18 2:13 ` Bin Meng
2019-09-18 10:04 ` Marek Vasut
0 siblings, 1 reply; 5+ messages in thread
From: Bin Meng @ 2019-09-18 2:13 UTC (permalink / raw)
To: u-boot
On Tue, Sep 17, 2019 at 10:43 PM Marek Vasut <marek.vasut@gmail.com> wrote:
>
> Due to constant influx of more and more weird and broken USB sticks,
> do as Linux does in commit 779b457f66e10de3471479373463b27fd308dc85
>
> usb: storage: scsiglue: further describe our 240 sector limit
>
> Just so we have some sort of documentation as to why
> we limit our Mass Storage transfers to 240 sectors,
> let's update the comment to make clearer that
> devices were found that would choke with larger
> transfers.
>
> While at that, also make sure to clarify that other
> operating systems have similar, albeit different,
> limits on mass storage transfers.
>
> And reduce the maximum transfer length of USB storage to 120 kiB.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
> Cc: Bin Meng <bmeng.cn@gmail.com>
> Cc: Simon Glass <sjg@chromium.org>
> ---
> V2: Reshuffle the code a bit, always clamp the transfer size to 240 blocks
> ---
> common/usb_storage.c | 43 ++++++++++++++++++++++---------------------
> 1 file changed, 22 insertions(+), 21 deletions(-)
>
> diff --git a/common/usb_storage.c b/common/usb_storage.c
> index 8c889bb1a6..e1b539a082 100644
> --- a/common/usb_storage.c
> +++ b/common/usb_storage.c
> @@ -938,31 +938,32 @@ do_retry:
> static void usb_stor_set_max_xfer_blk(struct usb_device *udev,
> struct us_data *us)
> {
> - unsigned short blk;
> - size_t __maybe_unused size;
> - int __maybe_unused ret;
> -
> -#if !CONFIG_IS_ENABLED(DM_USB)
> -#ifdef CONFIG_USB_EHCI_HCD
> /*
> - * The U-Boot EHCI driver can handle any transfer length as long as
> - * there is enough free heap space left, but the SCSI READ(10) and
> - * WRITE(10) commands are limited to 65535 blocks.
> + * Limit the total size of a transfer to 120 KB.
> + *
> + * Some devices are known to choke with anything larger. It seems like
> + * the problem stems from the fact that original IDE controllers had
> + * only an 8-bit register to hold the number of sectors in one transfer
> + * and even those couldn't handle a full 256 sectors.
> + *
> + * Because we want to make sure we interoperate with as many devices as
> + * possible, we will maintain a 240 sector transfer size limit for USB
> + * Mass Storage devices.
> + *
> + * Tests show that other operating have similar limits with Microsoft
> + * Windows 7 limiting transfers to 128 sectors for both USB2 and USB3
> + * and Apple Mac OS X 10.11 limiting transfers to 256 sectors for USB2
> + * and 2048 for USB3 devices.
> */
> - blk = USHRT_MAX;
> -#else
> - blk = 20;
> -#endif
> -#else
> + unsigned short blk = 240;
> +
> +#if CONFIG_IS_ENABLED(DM_USB)
> + size_t size;
> + int ret;
> +
> ret = usb_get_max_xfer_size(udev, (size_t *)&size);
> - if (ret < 0) {
> - /* unimplemented, let's use default 20 */
> - blk = 20;
> - } else {
> - if (size > USHRT_MAX * 512)
> - size = USHRT_MAX * 512;
> + if ((ret >= 0) && (size < 240 * 512))
size < blk * 512
> blk = size / 512;
> - }
> #endif
>
> us->max_xfer_blk = blk;
> --
Looks good otherwise
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [U-Boot] [PATCH V2] [RFC] usb: storage: Limit transfer size to 120 kiB
2019-09-18 2:13 ` Bin Meng
@ 2019-09-18 10:04 ` Marek Vasut
2019-09-18 10:27 ` Bin Meng
0 siblings, 1 reply; 5+ messages in thread
From: Marek Vasut @ 2019-09-18 10:04 UTC (permalink / raw)
To: u-boot
On 9/18/19 4:13 AM, Bin Meng wrote:
> On Tue, Sep 17, 2019 at 10:43 PM Marek Vasut <marek.vasut@gmail.com> wrote:
>>
>> Due to constant influx of more and more weird and broken USB sticks,
>> do as Linux does in commit 779b457f66e10de3471479373463b27fd308dc85
>>
>> usb: storage: scsiglue: further describe our 240 sector limit
>>
>> Just so we have some sort of documentation as to why
>> we limit our Mass Storage transfers to 240 sectors,
>> let's update the comment to make clearer that
>> devices were found that would choke with larger
>> transfers.
>>
>> While at that, also make sure to clarify that other
>> operating systems have similar, albeit different,
>> limits on mass storage transfers.
>>
>> And reduce the maximum transfer length of USB storage to 120 kiB.
>>
>> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
>> Cc: Bin Meng <bmeng.cn@gmail.com>
>> Cc: Simon Glass <sjg@chromium.org>
>> ---
>> V2: Reshuffle the code a bit, always clamp the transfer size to 240 blocks
>> ---
>> common/usb_storage.c | 43 ++++++++++++++++++++++---------------------
>> 1 file changed, 22 insertions(+), 21 deletions(-)
>>
>> diff --git a/common/usb_storage.c b/common/usb_storage.c
>> index 8c889bb1a6..e1b539a082 100644
>> --- a/common/usb_storage.c
>> +++ b/common/usb_storage.c
>> @@ -938,31 +938,32 @@ do_retry:
>> static void usb_stor_set_max_xfer_blk(struct usb_device *udev,
>> struct us_data *us)
>> {
>> - unsigned short blk;
>> - size_t __maybe_unused size;
>> - int __maybe_unused ret;
>> -
>> -#if !CONFIG_IS_ENABLED(DM_USB)
>> -#ifdef CONFIG_USB_EHCI_HCD
>> /*
>> - * The U-Boot EHCI driver can handle any transfer length as long as
>> - * there is enough free heap space left, but the SCSI READ(10) and
>> - * WRITE(10) commands are limited to 65535 blocks.
>> + * Limit the total size of a transfer to 120 KB.
>> + *
>> + * Some devices are known to choke with anything larger. It seems like
>> + * the problem stems from the fact that original IDE controllers had
>> + * only an 8-bit register to hold the number of sectors in one transfer
>> + * and even those couldn't handle a full 256 sectors.
>> + *
>> + * Because we want to make sure we interoperate with as many devices as
>> + * possible, we will maintain a 240 sector transfer size limit for USB
>> + * Mass Storage devices.
>> + *
>> + * Tests show that other operating have similar limits with Microsoft
>> + * Windows 7 limiting transfers to 128 sectors for both USB2 and USB3
>> + * and Apple Mac OS X 10.11 limiting transfers to 256 sectors for USB2
>> + * and 2048 for USB3 devices.
>> */
>> - blk = USHRT_MAX;
>> -#else
>> - blk = 20;
>> -#endif
>> -#else
>> + unsigned short blk = 240;
>> +
>> +#if CONFIG_IS_ENABLED(DM_USB)
>> + size_t size;
>> + int ret;
>> +
>> ret = usb_get_max_xfer_size(udev, (size_t *)&size);
>> - if (ret < 0) {
>> - /* unimplemented, let's use default 20 */
>> - blk = 20;
>> - } else {
>> - if (size > USHRT_MAX * 512)
>> - size = USHRT_MAX * 512;
>> + if ((ret >= 0) && (size < 240 * 512))
>
> size < blk * 512
>
>> blk = size / 512;
>> - }
>> #endif
>>
>> us->max_xfer_blk = blk;
>> --
>
> Looks good otherwise
>
> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Fixed and added to next . This really needs a LOT of testing.
I am worried about performance here.
--
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 5+ messages in thread
* [U-Boot] [PATCH V2] [RFC] usb: storage: Limit transfer size to 120 kiB
2019-09-18 10:04 ` Marek Vasut
@ 2019-09-18 10:27 ` Bin Meng
2019-09-18 15:03 ` Marek Vasut
0 siblings, 1 reply; 5+ messages in thread
From: Bin Meng @ 2019-09-18 10:27 UTC (permalink / raw)
To: u-boot
On Wed, Sep 18, 2019 at 6:07 PM Marek Vasut <marek.vasut@gmail.com> wrote:
>
> On 9/18/19 4:13 AM, Bin Meng wrote:
> > On Tue, Sep 17, 2019 at 10:43 PM Marek Vasut <marek.vasut@gmail.com> wrote:
> >>
> >> Due to constant influx of more and more weird and broken USB sticks,
> >> do as Linux does in commit 779b457f66e10de3471479373463b27fd308dc85
> >>
> >> usb: storage: scsiglue: further describe our 240 sector limit
> >>
> >> Just so we have some sort of documentation as to why
> >> we limit our Mass Storage transfers to 240 sectors,
> >> let's update the comment to make clearer that
> >> devices were found that would choke with larger
> >> transfers.
> >>
> >> While at that, also make sure to clarify that other
> >> operating systems have similar, albeit different,
> >> limits on mass storage transfers.
> >>
> >> And reduce the maximum transfer length of USB storage to 120 kiB.
> >>
> >> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
> >> Cc: Bin Meng <bmeng.cn@gmail.com>
> >> Cc: Simon Glass <sjg@chromium.org>
> >> ---
> >> V2: Reshuffle the code a bit, always clamp the transfer size to 240 blocks
> >> ---
> >> common/usb_storage.c | 43 ++++++++++++++++++++++---------------------
> >> 1 file changed, 22 insertions(+), 21 deletions(-)
> >>
> >> diff --git a/common/usb_storage.c b/common/usb_storage.c
> >> index 8c889bb1a6..e1b539a082 100644
> >> --- a/common/usb_storage.c
> >> +++ b/common/usb_storage.c
> >> @@ -938,31 +938,32 @@ do_retry:
> >> static void usb_stor_set_max_xfer_blk(struct usb_device *udev,
> >> struct us_data *us)
> >> {
> >> - unsigned short blk;
> >> - size_t __maybe_unused size;
> >> - int __maybe_unused ret;
> >> -
> >> -#if !CONFIG_IS_ENABLED(DM_USB)
> >> -#ifdef CONFIG_USB_EHCI_HCD
> >> /*
> >> - * The U-Boot EHCI driver can handle any transfer length as long as
> >> - * there is enough free heap space left, but the SCSI READ(10) and
> >> - * WRITE(10) commands are limited to 65535 blocks.
> >> + * Limit the total size of a transfer to 120 KB.
> >> + *
> >> + * Some devices are known to choke with anything larger. It seems like
> >> + * the problem stems from the fact that original IDE controllers had
> >> + * only an 8-bit register to hold the number of sectors in one transfer
> >> + * and even those couldn't handle a full 256 sectors.
> >> + *
> >> + * Because we want to make sure we interoperate with as many devices as
> >> + * possible, we will maintain a 240 sector transfer size limit for USB
> >> + * Mass Storage devices.
> >> + *
> >> + * Tests show that other operating have similar limits with Microsoft
> >> + * Windows 7 limiting transfers to 128 sectors for both USB2 and USB3
> >> + * and Apple Mac OS X 10.11 limiting transfers to 256 sectors for USB2
> >> + * and 2048 for USB3 devices.
> >> */
> >> - blk = USHRT_MAX;
> >> -#else
> >> - blk = 20;
> >> -#endif
> >> -#else
> >> + unsigned short blk = 240;
> >> +
> >> +#if CONFIG_IS_ENABLED(DM_USB)
> >> + size_t size;
> >> + int ret;
> >> +
> >> ret = usb_get_max_xfer_size(udev, (size_t *)&size);
> >> - if (ret < 0) {
> >> - /* unimplemented, let's use default 20 */
> >> - blk = 20;
> >> - } else {
> >> - if (size > USHRT_MAX * 512)
> >> - size = USHRT_MAX * 512;
> >> + if ((ret >= 0) && (size < 240 * 512))
> >
> > size < blk * 512
> >
> >> blk = size / 512;
> >> - }
> >> #endif
> >>
> >> us->max_xfer_blk = blk;
> >> --
> >
> > Looks good otherwise
> >
> > Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
>
> Fixed and added to next . This really needs a LOT of testing.
> I am worried about performance here.
Agree. I was wondering how Linux managed to set such limit for all usb
storage devices and no performance degradation reported?
BTW: it looks you missed adding my "Reviewed-by"
https://gitlab.denx.de/u-boot/custodians/u-boot-usb/commit/85a0cb96dabf7572db3c6726a276a48c5c77a9da
Regards,
Bin
^ permalink raw reply [flat|nested] 5+ messages in thread
* [U-Boot] [PATCH V2] [RFC] usb: storage: Limit transfer size to 120 kiB
2019-09-18 10:27 ` Bin Meng
@ 2019-09-18 15:03 ` Marek Vasut
0 siblings, 0 replies; 5+ messages in thread
From: Marek Vasut @ 2019-09-18 15:03 UTC (permalink / raw)
To: u-boot
On 9/18/19 12:27 PM, Bin Meng wrote:
> On Wed, Sep 18, 2019 at 6:07 PM Marek Vasut <marek.vasut@gmail.com> wrote:
>>
>> On 9/18/19 4:13 AM, Bin Meng wrote:
>>> On Tue, Sep 17, 2019 at 10:43 PM Marek Vasut <marek.vasut@gmail.com> wrote:
>>>>
>>>> Due to constant influx of more and more weird and broken USB sticks,
>>>> do as Linux does in commit 779b457f66e10de3471479373463b27fd308dc85
>>>>
>>>> usb: storage: scsiglue: further describe our 240 sector limit
>>>>
>>>> Just so we have some sort of documentation as to why
>>>> we limit our Mass Storage transfers to 240 sectors,
>>>> let's update the comment to make clearer that
>>>> devices were found that would choke with larger
>>>> transfers.
>>>>
>>>> While at that, also make sure to clarify that other
>>>> operating systems have similar, albeit different,
>>>> limits on mass storage transfers.
>>>>
>>>> And reduce the maximum transfer length of USB storage to 120 kiB.
>>>>
>>>> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
>>>> Cc: Bin Meng <bmeng.cn@gmail.com>
>>>> Cc: Simon Glass <sjg@chromium.org>
>>>> ---
>>>> V2: Reshuffle the code a bit, always clamp the transfer size to 240 blocks
>>>> ---
>>>> common/usb_storage.c | 43 ++++++++++++++++++++++---------------------
>>>> 1 file changed, 22 insertions(+), 21 deletions(-)
>>>>
>>>> diff --git a/common/usb_storage.c b/common/usb_storage.c
>>>> index 8c889bb1a6..e1b539a082 100644
>>>> --- a/common/usb_storage.c
>>>> +++ b/common/usb_storage.c
>>>> @@ -938,31 +938,32 @@ do_retry:
>>>> static void usb_stor_set_max_xfer_blk(struct usb_device *udev,
>>>> struct us_data *us)
>>>> {
>>>> - unsigned short blk;
>>>> - size_t __maybe_unused size;
>>>> - int __maybe_unused ret;
>>>> -
>>>> -#if !CONFIG_IS_ENABLED(DM_USB)
>>>> -#ifdef CONFIG_USB_EHCI_HCD
>>>> /*
>>>> - * The U-Boot EHCI driver can handle any transfer length as long as
>>>> - * there is enough free heap space left, but the SCSI READ(10) and
>>>> - * WRITE(10) commands are limited to 65535 blocks.
>>>> + * Limit the total size of a transfer to 120 KB.
>>>> + *
>>>> + * Some devices are known to choke with anything larger. It seems like
>>>> + * the problem stems from the fact that original IDE controllers had
>>>> + * only an 8-bit register to hold the number of sectors in one transfer
>>>> + * and even those couldn't handle a full 256 sectors.
>>>> + *
>>>> + * Because we want to make sure we interoperate with as many devices as
>>>> + * possible, we will maintain a 240 sector transfer size limit for USB
>>>> + * Mass Storage devices.
>>>> + *
>>>> + * Tests show that other operating have similar limits with Microsoft
>>>> + * Windows 7 limiting transfers to 128 sectors for both USB2 and USB3
>>>> + * and Apple Mac OS X 10.11 limiting transfers to 256 sectors for USB2
>>>> + * and 2048 for USB3 devices.
>>>> */
>>>> - blk = USHRT_MAX;
>>>> -#else
>>>> - blk = 20;
>>>> -#endif
>>>> -#else
>>>> + unsigned short blk = 240;
>>>> +
>>>> +#if CONFIG_IS_ENABLED(DM_USB)
>>>> + size_t size;
>>>> + int ret;
>>>> +
>>>> ret = usb_get_max_xfer_size(udev, (size_t *)&size);
>>>> - if (ret < 0) {
>>>> - /* unimplemented, let's use default 20 */
>>>> - blk = 20;
>>>> - } else {
>>>> - if (size > USHRT_MAX * 512)
>>>> - size = USHRT_MAX * 512;
>>>> + if ((ret >= 0) && (size < 240 * 512))
>>>
>>> size < blk * 512
>>>
>>>> blk = size / 512;
>>>> - }
>>>> #endif
>>>>
>>>> us->max_xfer_blk = blk;
>>>> --
>>>
>>> Looks good otherwise
>>>
>>> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
>>
>> Fixed and added to next . This really needs a LOT of testing.
>> I am worried about performance here.
>
> Agree. I was wondering how Linux managed to set such limit for all usb
> storage devices and no performance degradation reported?
I suspect they create a new QH/qTD chain during the transfer and load it
into the controller right when the previous one finishes.
> BTW: it looks you missed adding my "Reviewed-by"
> https://gitlab.denx.de/u-boot/custodians/u-boot-usb/commit/85a0cb96dabf7572db3c6726a276a48c5c77a9da
Should be fixed now.
--
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-09-18 15:03 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-09-17 14:43 [U-Boot] [PATCH V2] [RFC] usb: storage: Limit transfer size to 120 kiB Marek Vasut
2019-09-18 2:13 ` Bin Meng
2019-09-18 10:04 ` Marek Vasut
2019-09-18 10:27 ` Bin Meng
2019-09-18 15:03 ` Marek Vasut
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