]> git.ipfire.org Git - people/arne_f/kernel.git/commit
usb: gadget: Fix issue with config_ep_by_speed function
authorPawel Laszczak <pawell@cadence.com>
Mon, 18 May 2020 10:08:45 +0000 (12:08 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 25 Jun 2020 13:41:55 +0000 (15:41 +0200)
commit0c8c366c54f07f70d03260db9e0faa52f8d65749
treeab2a488e6dd719c09e03987e206d37025b61ce5e
parent264175bd94374683d4b0f4944294b44878defe87
usb: gadget: Fix issue with config_ep_by_speed function

[ Upstream commit 5d363120aa548ba52d58907a295eee25f8207ed2 ]

This patch adds new config_ep_by_speed_and_alt function which
extends the config_ep_by_speed about alt parameter.
This additional parameter allows to find proper usb_ss_ep_comp_descriptor.

Problem has appeared during testing f_tcm (BOT/UAS) driver function.

f_tcm function for SS use array of headers for both  BOT/UAS alternate
setting:

static struct usb_descriptor_header *uasp_ss_function_desc[] = {
        (struct usb_descriptor_header *) &bot_intf_desc,
        (struct usb_descriptor_header *) &uasp_ss_bi_desc,
        (struct usb_descriptor_header *) &bot_bi_ep_comp_desc,
        (struct usb_descriptor_header *) &uasp_ss_bo_desc,
        (struct usb_descriptor_header *) &bot_bo_ep_comp_desc,

        (struct usb_descriptor_header *) &uasp_intf_desc,
        (struct usb_descriptor_header *) &uasp_ss_bi_desc,
        (struct usb_descriptor_header *) &uasp_bi_ep_comp_desc,
        (struct usb_descriptor_header *) &uasp_bi_pipe_desc,
        (struct usb_descriptor_header *) &uasp_ss_bo_desc,
        (struct usb_descriptor_header *) &uasp_bo_ep_comp_desc,
        (struct usb_descriptor_header *) &uasp_bo_pipe_desc,
        (struct usb_descriptor_header *) &uasp_ss_status_desc,
        (struct usb_descriptor_header *) &uasp_status_in_ep_comp_desc,
        (struct usb_descriptor_header *) &uasp_status_pipe_desc,
        (struct usb_descriptor_header *) &uasp_ss_cmd_desc,
        (struct usb_descriptor_header *) &uasp_cmd_comp_desc,
        (struct usb_descriptor_header *) &uasp_cmd_pipe_desc,
        NULL,
};

The first 5 descriptors are associated with BOT alternate setting,
and others are associated with UAS.

During handling UAS alternate setting f_tcm driver invokes
config_ep_by_speed and this function sets incorrect companion endpoint
descriptor in usb_ep object.

Instead setting ep->comp_desc to uasp_bi_ep_comp_desc function in this
case set ep->comp_desc to uasp_ss_bi_desc.

This is due to the fact that it searches endpoint based on endpoint
address:

        for_each_ep_desc(speed_desc, d_spd) {
                chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
                if (chosen_desc->bEndpoitAddress == _ep->address)
                        goto ep_found;
        }

And in result it uses the descriptor from BOT alternate setting
instead UAS.

Finally, it causes that controller driver during enabling endpoints
detect that just enabled endpoint for bot.

Signed-off-by: Jayshri Pawar <jpawar@cadence.com>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/usb/gadget/composite.c
include/linux/usb/composite.h