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usb: gadget: Fix issue with config_ep_by_speed function 

[ Upstream commit 5d363120aa ]

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>
5.4-rM2-2.2.x-imx-squashed
Pawel Laszczak 2020-05-18 12:08:45 +02:00 committed by Greg Kroah-Hartman
parent 84e1326ffc
commit c707e18796
2 changed files with 64 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

78
drivers/usb/gadget/composite.c
View File

@ -96,40 +96,43 @@ function_descriptors(struct usb_function *f,
}
/**
* next_ep_desc() - advance to the next EP descriptor
* next_desc() - advance to the next desc_type descriptor
* @t: currect pointer within descriptor array
* @desc_type: descriptor type
*
* Return: next EP descriptor or NULL
* Return: next desc_type descriptor or NULL
*
* Iterate over @t until either EP descriptor found or
* Iterate over @t until either desc_type descriptor found or
* NULL (that indicates end of list) encountered
*/
static struct usb_descriptor_header**
next_ep_desc(struct usb_descriptor_header **t)
next_desc(struct usb_descriptor_header **t, u8 desc_type)
{
for (; *t; t++) {
if ((*t)->bDescriptorType == USB_DT_ENDPOINT)
if ((*t)->bDescriptorType == desc_type)
return t;
}
return NULL;
}
/*
* for_each_ep_desc()- iterate over endpoint descriptors in the
* descriptors list
* @start: pointer within descriptor array.
* @ep_desc: endpoint descriptor to use as the loop cursor
* for_each_desc() - iterate over desc_type descriptors in the
* descriptors list
* @start: pointer within descriptor array.
* @iter_desc: desc_type descriptor to use as the loop cursor
* @desc_type: wanted descriptr type
*/
#define for_each_ep_desc(start, ep_desc) \
for (ep_desc = next_ep_desc(start); \
ep_desc; ep_desc = next_ep_desc(ep_desc+1))
#define for_each_desc(start, iter_desc, desc_type) \
for (iter_desc = next_desc(start, desc_type); \
iter_desc; iter_desc = next_desc(iter_desc + 1, desc_type))
/**
* config_ep_by_speed() - configures the given endpoint
* config_ep_by_speed_and_alt() - configures the given endpoint
* according to gadget speed.
* @g: pointer to the gadget
* @f: usb function
* @_ep: the endpoint to configure
* @alt: alternate setting number
*
* Return: error code, 0 on success
*
@ -142,11 +145,13 @@ next_ep_desc(struct usb_descriptor_header **t)
* Note: the supplied function should hold all the descriptors
* for supported speeds
*/
int config_ep_by_speed(struct usb_gadget *g,
struct usb_function *f,
struct usb_ep *_ep)
int config_ep_by_speed_and_alt(struct usb_gadget *g,
struct usb_function *f,
struct usb_ep *_ep,
u8 alt)
{
struct usb_endpoint_descriptor *chosen_desc = NULL;
struct usb_interface_descriptor *int_desc = NULL;
struct usb_descriptor_header **speed_desc = NULL;
struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
@ -182,8 +187,21 @@ int config_ep_by_speed(struct usb_gadget *g,
default:
speed_desc = f->fs_descriptors;
}
/* find correct alternate setting descriptor */
for_each_desc(speed_desc, d_spd, USB_DT_INTERFACE) {
int_desc = (struct usb_interface_descriptor *)*d_spd;
if (int_desc->bAlternateSetting == alt) {
speed_desc = d_spd;
goto intf_found;
}
}
return -EIO;
intf_found:
/* find descriptors */
for_each_ep_desc(speed_desc, d_spd) {
for_each_desc(speed_desc, d_spd, USB_DT_ENDPOINT) {
chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
if (chosen_desc->bEndpointAddress == _ep->address)
goto ep_found;
@ -237,6 +255,32 @@ ep_found:
}
return 0;
}
EXPORT_SYMBOL_GPL(config_ep_by_speed_and_alt);
/**
* config_ep_by_speed() - configures the given endpoint
* according to gadget speed.
* @g: pointer to the gadget
* @f: usb function
* @_ep: the endpoint to configure
*
* Return: error code, 0 on success
*
* This function chooses the right descriptors for a given
* endpoint according to gadget speed and saves it in the
* endpoint desc field. If the endpoint already has a descriptor
* assigned to it - overwrites it with currently corresponding
* descriptor. The endpoint maxpacket field is updated according
* to the chosen descriptor.
* Note: the supplied function should hold all the descriptors
* for supported speeds
*/
int config_ep_by_speed(struct usb_gadget *g,
struct usb_function *f,
struct usb_ep *_ep)
{
return config_ep_by_speed_and_alt(g, f, _ep, 0);
}
EXPORT_SYMBOL_GPL(config_ep_by_speed);
/**

3
include/linux/usb/composite.h
View File

@ -249,6 +249,9 @@ int usb_function_activate(struct usb_function *);
int usb_interface_id(struct usb_configuration *, struct usb_function *);
int config_ep_by_speed_and_alt(struct usb_gadget *g, struct usb_function *f,
struct usb_ep *_ep, u8 alt);
int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
struct usb_ep *_ep);