From: Jack Pham jackp@codeaurora.org
commit a353397b0d5dfa3c99b372505db3378fc919c6c6 upstream.
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(-)
--- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -1332,6 +1332,7 @@ static long ffs_epfile_ioctl(struct file
switch (epfile->ffs->gadget->speed) { case USB_SPEED_SUPER: + case USB_SPEED_SUPER_PLUS: desc_idx = 2; break; case USB_SPEED_HIGH: @@ -3193,7 +3194,8 @@ static int _ffs_func_bind(struct usb_con }
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, @@ -3603,6 +3605,7 @@ static void ffs_func_unbind(struct usb_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);