This is a note to let you know that I've just added the patch titled
usb: gadget: f_fs: Re-use SS descriptors for SuperSpeedPlus
to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-next branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release during the merge window.
If you have any questions about this process, please let me know.
From a353397b0d5dfa3c99b372505db3378fc919c6c6 Mon Sep 17 00:00:00 2001
From: Jack Pham jackp@codeaurora.org Date: Tue, 27 Oct 2020 16:07:31 -0700 Subject: usb: gadget: f_fs: Re-use SS descriptors for SuperSpeedPlus
In many cases a function that supports SuperSpeed can very well operate in SuperSpeedPlus, if a gadget controller supports it, as the endpoint descriptors (and companion descriptors) are generally identical and can be re-used. This is true for two commonly used functions: Android's ADB and MTP. So we can simply assign the usb_function's ssp_descriptors array to point to its ss_descriptors, if available. Similarly, we need to allow an epfile's ioctl for FUNCTIONFS_ENDPOINT_DESC to correctly return the corresponding SuperSpeed endpoint descriptor in case the connected speed is SuperSpeedPlus as well.
The only exception is if a function wants to implement an Isochronous endpoint capable of transferring more than 48KB per service interval when operating at greater than USB 3.1 Gen1 speed, in which case it would require an additional SuperSpeedPlus Isochronous Endpoint Companion descriptor to be returned as part of the Configuration Descriptor. Support for that would need to be separately added to the userspace-facing FunctionFS API which may not be a trivial task--likely a new descriptor format (v3?) may need to be devised to allow for separate SS and SSP descriptors to be supplied.
Signed-off-by: Jack Pham jackp@codeaurora.org Cc: stable stable@vger.kernel.org Link: https://lore.kernel.org/r/20201027230731.9073-1-jackp@codeaurora.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/gadget/function/f_fs.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 8f5ceacdc5f1..78c003fb05fd 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -1330,6 +1330,7 @@ static long ffs_epfile_ioctl(struct file *file, unsigned code,
switch (epfile->ffs->gadget->speed) { case USB_SPEED_SUPER: + case USB_SPEED_SUPER_PLUS: desc_idx = 2; break; case USB_SPEED_HIGH: @@ -3176,7 +3177,8 @@ static int _ffs_func_bind(struct usb_configuration *c, }
if (likely(super)) { - func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs); + func->function.ss_descriptors = func->function.ssp_descriptors = + vla_ptr(vlabuf, d, ss_descs); ss_len = ffs_do_descs(ffs->ss_descs_count, vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len, d_raw_descs__sz - fs_len - hs_len, @@ -3586,6 +3588,7 @@ static void ffs_func_unbind(struct usb_configuration *c, func->function.fs_descriptors = NULL; func->function.hs_descriptors = NULL; func->function.ss_descriptors = NULL; + func->function.ssp_descriptors = NULL; func->interfaces_nums = NULL;
ffs_event_add(ffs, FUNCTIONFS_UNBIND);