Re: [PATCH 07/34] brcmfmac: Remove brcmf_sdiod_request_data()
On 19-08-17 22:02, Ian Molton wrote:
On 07/08/17 18:51, Ian Molton wrote:
On 07/08/17 12:25, Arend van Spriel wrote:
Handling of -ENOMEDIUM is altered, but as that's pretty much broken
anyway
we can ignore that.
Please explain why you think it is broken.
Not got the code to hand right now, but from memory, theres a trapdoor
case where the state can wind up set to something that prevents it ever
being changed again. I'll dig it up when I get back from holiday (this
next few days).
Hi,
Here is the function I had in mind:
void brcmf_sdiod_change_state(struct brcmf_sdio_dev *sdiodev,
enum brcmf_sdiod_state state)
{
if (sdiodev->state == BRCMF_SDIOD_NOMEDIUM ||
state == sdiodev->state)
return;
brcmf_dbg(TRACE, "%d -> %d\n", sdiodev->state, state);
switch (sdiodev->state) {
case BRCMF_SDIOD_DATA:
/* any other state means bus interface is down */
brcmf_bus_change_state(sdiodev->bus_if, BRCMF_BUS_DOWN);
break;
case BRCMF_SDIOD_DOWN:
/* transition from DOWN to DATA means bus interface is up */
if (state == BRCMF_SDIOD_DATA)
brcmf_bus_change_state(sdiodev->bus_if,
BRCMF_BUS_UP);
break;
default:
break;
}
sdiodev->state = state;
}
If it's *ever* called with state = BRCMF_SDIOD_NOMEDIUM it will
eventually (last line) set sdiodev->state to the same value.
If its ever called again, the first if() statement will make it return
before ever changing sdiodev->state again, no matter what value is
passed for state.
This has to be a bug, surely?
I thought I already responded this email. So it is not a bug. It really
was made like this intentional. It is the end state of this little FSM.
The thing is that there was no way to recover. Maybe nowadays with the
MMC stack being able to power sequence the device (provided it is
properly configured in device tree) we may get lucky using
mmc_hw_reset(). But now you need to consider how many times to call that
before giving up and what driver components/states need to be reset as
well. So I would prefer to keep the current behavior until a more
graceful approach has been designed and implemented to replace it.
Regards,
Arend
Re: [PATCH 07/34] brcmfmac: Remove brcmf_sdiod_request_data()
On 07/08/17 18:51, Ian Molton wrote:
> On 07/08/17 12:25, Arend van Spriel wrote:
>>> Handling of -ENOMEDIUM is altered, but as that's pretty much broken
>>> anyway
>>> we can ignore that.
>>
>> Please explain why you think it is broken.
>
> Not got the code to hand right now, but from memory, theres a trapdoor
> case where the state can wind up set to something that prevents it ever
> being changed again. I'll dig it up when I get back from holiday (this
> next few days).
Hi,
Here is the function I had in mind:
void brcmf_sdiod_change_state(struct brcmf_sdio_dev *sdiodev,
enum brcmf_sdiod_state state)
{
if (sdiodev->state == BRCMF_SDIOD_NOMEDIUM ||
state == sdiodev->state)
return;
brcmf_dbg(TRACE, "%d -> %d\n", sdiodev->state, state);
switch (sdiodev->state) {
case BRCMF_SDIOD_DATA:
/* any other state means bus interface is down */
brcmf_bus_change_state(sdiodev->bus_if, BRCMF_BUS_DOWN);
break;
case BRCMF_SDIOD_DOWN:
/* transition from DOWN to DATA means bus interface is up */
if (state == BRCMF_SDIOD_DATA)
brcmf_bus_change_state(sdiodev->bus_if,
BRCMF_BUS_UP);
break;
default:
break;
}
sdiodev->state = state;
}
If it's *ever* called with state = BRCMF_SDIOD_NOMEDIUM it will
eventually (last line) set sdiodev->state to the same value.
If its ever called again, the first if() statement will make it return
before ever changing sdiodev->state again, no matter what value is
passed for state.
This has to be a bug, surely?
-Ian
Re: [PATCH 07/34] brcmfmac: Remove brcmf_sdiod_request_data()
On 07/08/17 12:25, Arend van Spriel wrote: >> Handling of -ENOMEDIUM is altered, but as that's pretty much broken >> anyway >> we can ignore that. > > Please explain why you think it is broken. Not got the code to hand right now, but from memory, theres a trapdoor case where the state can wind up set to something that prevents it ever being changed again. I'll dig it up when I get back from holiday (this next few days). -Ian
Re: [PATCH 07/34] brcmfmac: Remove brcmf_sdiod_request_data()
On 26-07-17 22:25, Ian Molton wrote:
This function is obfuscating how IO works on this chip. Remove it
and push its logic into brcmf_sdiod_reg_{read,write}().
Handling of -ENOMEDIUM is altered, but as that's pretty much broken anyway
we can ignore that.
Please explain why you think it is broken.
Reviewed-by: Arend van Spriel
Signed-off-by: Ian Molton
more comments below.
# Conflicts:
# drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
---
.../wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c | 239 -
.../wireless/broadcom/brcm80211/brcmfmac/sdio.h| 2 +-
2 files changed, 87 insertions(+), 154 deletions(-)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
index d217b1281e0d..f703d7be6a85 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
[...]
static int brcmf_sdiod_reg_write(struct brcmf_sdio_dev *sdiodev, u32 addr,
u8 regsz, void *data)
{
- u8 func;
- s32 retry = 0;
int ret;
- if (sdiodev->state == BRCMF_SDIOD_NOMEDIUM)
- return -ENOMEDIUM;
-
/*
* figure out how to read the register based on address range
* 0x00 ~ 0x7FF: function 0 CCCR and FBR
* 0x1 ~ 0x1: function 1 miscellaneous registers
* The rest: function 1 silicon backplane core registers
+* f0 writes must be bytewise
*/
- if ((addr & ~REG_F0_REG_MASK) == 0)
- func = SDIO_FUNC_0;
- else
- func = SDIO_FUNC_1;
-
- do {
- /* for retry wait for 1 ms till bus get settled down */
- if (retry)
- usleep_range(1000, 2000);
- ret = brcmf_sdiod_request_data(sdiodev, func, addr, regsz,
- data, true);
-
- } while (ret != 0 && ret != -ENOMEDIUM &&
-retry++ < SDIOH_API_ACCESS_RETRY_LIMIT);
+ if ((addr & ~REG_F0_REG_MASK) == 0) {
+ if (WARN_ON(regsz > 1))
+ return -EINVAL;
+ ret = brcmf_sdiod_f0_writeb(sdiodev->func[0], *(u8 *)data,
addr);
+ } else {
+ switch (regsz) {
+ case 1:
+ sdio_writeb(sdiodev->func[1], *(u8 *)data, addr, );
+ break;
+ case 4:
+ ret = brcmf_sdiod_addrprep(sdiodev, );
+ if (ret)
+ goto done;
- if (ret == -ENOMEDIUM)
- brcmf_sdiod_change_state(sdiodev, BRCMF_SDIOD_NOMEDIUM);
+ sdio_writel(sdiodev->func[1], *(u32 *)data, addr, );
+ break;
+ default:
+ BUG();
Please do not use BUG() as it simply crashes the system. You may argue
that we never reach this unless a coding mistake is made, but still we
prefer WARN() over BUG() in such cases.
+ ret = -EINVAL;
+ break;
+ }
+ }
+done:
return ret;
}
static int brcmf_sdiod_reg_read(struct brcmf_sdio_dev *sdiodev, u32 addr,
u8 regsz, void *data)
{
- u8 func;
- s32 retry = 0;
int ret;
- if (sdiodev->state == BRCMF_SDIOD_NOMEDIUM)
- return -ENOMEDIUM;
-
/*
* figure out how to read the register based on address range
* 0x00 ~ 0x7FF: function 0 CCCR and FBR
* 0x1 ~ 0x1: function 1 miscellaneous registers
* The rest: function 1 silicon backplane core registers
+* f0 reads must be bytewise
*/
- if ((addr & ~REG_F0_REG_MASK) == 0)
- func = SDIO_FUNC_0;
- else
- func = SDIO_FUNC_1;
-
- do {
- memset(data, 0, regsz);
-
- /* for retry wait for 1 ms till bus get settled down */
- if (retry)
- usleep_range(1000, 2000);
-
- ret = brcmf_sdiod_request_data(sdiodev, func, addr, regsz,
- data, false);
-
- } while (ret != 0 && ret != -ENOMEDIUM &&
-retry++ < SDIOH_API_ACCESS_RETRY_LIMIT);
-
- if (ret == -ENOMEDIUM)
- brcmf_sdiod_change_state(sdiodev, BRCMF_SDIOD_NOMEDIUM);
-
- return ret;
-}
-
-static int
-brcmf_sdiod_set_sbaddr_window(struct brcmf_sdio_dev *sdiodev, u32 address)
-{
- int err = 0, i;
- u32 addr;
-
- if (sdiodev->state == BRCMF_SDIOD_NOMEDIUM)
- return -ENOMEDIUM;
-
- addr = (address & SBSDIO_SBWINDOW_MASK) >> 8;
-
- for (i = 0 ; i < 3 && !err ; i++, addr >>= 8)
- brcmf_sdiod_regwb(sdiodev,
[PATCH 07/34] brcmfmac: Remove brcmf_sdiod_request_data()
This function is obfuscating how IO works on this chip. Remove it
and push its logic into brcmf_sdiod_reg_{read,write}().
Handling of -ENOMEDIUM is altered, but as that's pretty much broken anyway
we can ignore that.
Signed-off-by: Ian Molton
# Conflicts:
# drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
---
.../wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c | 239 -
.../wireless/broadcom/brcm80211/brcmfmac/sdio.h| 2 +-
2 files changed, 87 insertions(+), 154 deletions(-)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
index d217b1281e0d..f703d7be6a85 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
@@ -230,6 +230,43 @@ void brcmf_sdiod_change_state(struct brcmf_sdio_dev
*sdiodev,
sdiodev->state = state;
}
+static int brcmf_sdiod_set_sbaddr_window(struct brcmf_sdio_dev *sdiodev,
+u32 address)
+{
+ int err = 0, i;
+ u32 addr;
+
+ if (sdiodev->state == BRCMF_SDIOD_NOMEDIUM)
+ return -ENOMEDIUM;
+
+ addr = (address & SBSDIO_SBWINDOW_MASK) >> 8;
+
+ for (i = 0 ; i < 3 && !err ; i++, addr >>= 8)
+ brcmf_sdiod_regwb(sdiodev, SBSDIO_FUNC1_SBADDRLOW + i,
+ addr & 0xff, );
+
+ return err;
+}
+
+static int brcmf_sdiod_addrprep(struct brcmf_sdio_dev *sdiodev, u32 *addr)
+{
+ uint bar0 = *addr & ~SBSDIO_SB_OFT_ADDR_MASK;
+ int err = 0;
+
+ if (bar0 != sdiodev->sbwad) {
+ err = brcmf_sdiod_set_sbaddr_window(sdiodev, bar0);
+ if (err)
+ return err;
+
+ sdiodev->sbwad = bar0;
+ }
+
+ *addr &= SBSDIO_SB_OFT_ADDR_MASK;
+ *addr |= SBSDIO_SB_ACCESS_2_4B_FLAG;
+
+ return 0;
+}
+
static inline int brcmf_sdiod_f0_writeb(struct sdio_func *func, u8 byte,
uint regaddr)
{
@@ -249,173 +286,83 @@ static inline int brcmf_sdiod_f0_writeb(struct sdio_func
*func, u8 byte,
return err_ret;
}
-static int brcmf_sdiod_request_data(struct brcmf_sdio_dev *sdiodev, u8 fn,
- u32 addr, u8 regsz, void *data, bool write)
-{
- struct sdio_func *func;
- int ret = -EINVAL;
-
- brcmf_dbg(SDIO, "rw=%d, func=%d, addr=0x%05x, nbytes=%d\n",
- write, fn, addr, regsz);
-
- /* only allow byte access on F0 */
- if (WARN_ON(regsz > 1 && !fn))
- return -EINVAL;
- func = sdiodev->func[fn];
-
- switch (regsz) {
- case 1:
- if (write) {
- if (fn)
- sdio_writeb(func, *(u8 *)data, addr, );
- else
- ret = brcmf_sdiod_f0_writeb(func, *(u8 *)data,
- addr);
- } else {
- if (fn)
- *(u8 *)data = sdio_readb(func, addr, );
- else
- *(u8 *)data = sdio_f0_readb(func, addr, );
- }
- break;
- case 2:
- if (write)
- sdio_writew(func, *(u16 *)data, addr, );
- else
- *(u16 *)data = sdio_readw(func, addr, );
- break;
- case 4:
- if (write)
- sdio_writel(func, *(u32 *)data, addr, );
- else
- *(u32 *)data = sdio_readl(func, addr, );
- break;
- default:
- brcmf_err("invalid size: %d\n", regsz);
- break;
- }
-
- if (ret)
- brcmf_dbg(SDIO, "failed to %s data F%d@0x%05x, err: %d\n",
- write ? "write" : "read", fn, addr, ret);
-
- return ret;
-}
-
static int brcmf_sdiod_reg_write(struct brcmf_sdio_dev *sdiodev, u32 addr,
u8 regsz, void *data)
{
- u8 func;
- s32 retry = 0;
int ret;
- if (sdiodev->state == BRCMF_SDIOD_NOMEDIUM)
- return -ENOMEDIUM;
-
/*
* figure out how to read the register based on address range
* 0x00 ~ 0x7FF: function 0 CCCR and FBR
* 0x1 ~ 0x1: function 1 miscellaneous registers
* The rest: function 1 silicon backplane core registers
+* f0 writes must be bytewise
*/
- if ((addr & ~REG_F0_REG_MASK) == 0)
- func = SDIO_FUNC_0;
- else
- func = SDIO_FUNC_1;
-
- do {
- /* for retry wait for 1 ms till bus get settled down */
- if (retry)
- usleep_range(1000, 2000);
- ret =
[PATCH 07/34] brcmfmac: Remove brcmf_sdiod_request_data()
This function is obfuscating how IO works on this chip. Remove it
and push its logic into brcmf_sdiod_reg_{read,write}().
Handling of -ENOMEDIUM is altered, but as that's pretty much broken anyway
we can ignore that.
Signed-off-by: Ian Molton
---
.../wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c | 241 -
.../wireless/broadcom/brcm80211/brcmfmac/sdio.h| 2 +-
2 files changed, 90 insertions(+), 153 deletions(-)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
index 7eb54539a85e..6df12430a43f 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
@@ -230,6 +230,44 @@ void brcmf_sdiod_change_state(struct brcmf_sdio_dev
*sdiodev,
sdiodev->state = state;
}
+static int
+brcmf_sdiod_set_sbaddr_window(struct brcmf_sdio_dev *sdiodev, u32 address)
+{
+ int err = 0, i;
+ u32 addr;
+
+ if (sdiodev->state == BRCMF_SDIOD_NOMEDIUM)
+ return -ENOMEDIUM;
+
+ addr = (address & SBSDIO_SBWINDOW_MASK) >> 8;
+
+ for ( i = 0 ; i < 3 && !err ; i++, addr >>= 8 )
+ brcmf_sdiod_regwb(sdiodev, SBSDIO_FUNC1_SBADDRLOW + i, addr &
0xff,
+ );
+
+ return err;
+}
+
+static int
+brcmf_sdiod_addrprep(struct brcmf_sdio_dev *sdiodev, u32 *addr)
+{
+ uint bar0 = *addr & ~SBSDIO_SB_OFT_ADDR_MASK;
+ int err = 0;
+
+ if (bar0 != sdiodev->sbwad) {
+ err = brcmf_sdiod_set_sbaddr_window(sdiodev, bar0);
+ if (err)
+ return err;
+
+ sdiodev->sbwad = bar0;
+ }
+
+ *addr &= SBSDIO_SB_OFT_ADDR_MASK;
+ *addr |= SBSDIO_SB_ACCESS_2_4B_FLAG;
+
+ return 0;
+}
+
static inline int brcmf_sdiod_f0_writeb(struct sdio_func *func, u8 byte, uint
regaddr)
{
int err_ret;
@@ -248,172 +286,85 @@ static inline int brcmf_sdiod_f0_writeb(struct sdio_func
*func, u8 byte, uint re
return err_ret;
}
-static int brcmf_sdiod_request_data(struct brcmf_sdio_dev *sdiodev, u8 fn,
- u32 addr, u8 regsz, void *data, bool write)
-{
- struct sdio_func *func;
- int ret = -EINVAL;
-
- brcmf_dbg(SDIO, "rw=%d, func=%d, addr=0x%05x, nbytes=%d\n",
- write, fn, addr, regsz);
-
- /* only allow byte access on F0 */
- if (WARN_ON(regsz > 1 && !fn))
- return -EINVAL;
- func = sdiodev->func[fn];
-
- switch (regsz) {
- case 1:
- if (write) {
- if (fn)
- sdio_writeb(func, *(u8 *)data, addr, );
- else
- ret = brcmf_sdiod_f0_writeb(func, *(u8 *)data,
addr);
- } else {
- if (fn)
- *(u8 *)data = sdio_readb(func, addr, );
- else
- *(u8 *)data = sdio_f0_readb(func, addr, );
- }
- break;
- case 2:
- if (write)
- sdio_writew(func, *(u16 *)data, addr, );
- else
- *(u16 *)data = sdio_readw(func, addr, );
- break;
- case 4:
- if (write)
- sdio_writel(func, *(u32 *)data, addr, );
- else
- *(u32 *)data = sdio_readl(func, addr, );
- break;
- default:
- brcmf_err("invalid size: %d\n", regsz);
- break;
- }
-
- if (ret)
- brcmf_dbg(SDIO, "failed to %s data F%d@0x%05x, err: %d\n",
- write ? "write" : "read", fn, addr, ret);
-
- return ret;
-}
-
static int brcmf_sdiod_reg_write(struct brcmf_sdio_dev *sdiodev, u32 addr,
u8 regsz, void *data)
{
- u8 func;
- s32 retry = 0;
int ret;
- if (sdiodev->state == BRCMF_SDIOD_NOMEDIUM)
- return -ENOMEDIUM;
-
/*
* figure out how to read the register based on address range
* 0x00 ~ 0x7FF: function 0 CCCR and FBR
* 0x1 ~ 0x1: function 1 miscellaneous registers
* The rest: function 1 silicon backplane core registers
+* f0 writes must be bytewise
*/
- if ((addr & ~REG_F0_REG_MASK) == 0)
- func = SDIO_FUNC_0;
- else
- func = SDIO_FUNC_1;
-
- do {
- /* for retry wait for 1 ms till bus get settled down */
- if (retry)
- usleep_range(1000, 2000);
- ret = brcmf_sdiod_request_data(sdiodev, func, addr, regsz,
- data, true);
-
- } while (ret != 0 && ret != -ENOMEDIUM &&
-retry++ <
