2009-11-06 15:56:04

by Martin Fuzzey

Subject: [PATCH] SSB: fix 32 bit PCMCIA access.

The scan function was using 32 bit access which does not
work on 16bit CF cards.

This patch corrects this by doing two 16 bit reads like
ssb_pcmcia_read32 already does (unfortunately we don't
have a struct ssb_device to use that directly).

Signed-off-by: Martin Fuzzey <[email protected]>

---

drivers/ssb/scan.c | 9 ++++++++-
1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/drivers/ssb/scan.c b/drivers/ssb/scan.c
index b74212d..6721fa8 100644
--- a/drivers/ssb/scan.c
+++ b/drivers/ssb/scan.c
@@ -162,6 +162,9 @@ static u8 chipid_to_nrcores(u16 chipid)
static u32 scan_read32(struct ssb_bus *bus, u8 current_coreidx,
u16 offset)
{
+ unsigned long flags;
+ u32 lo, hi;
+
switch (bus->bustype) {
case SSB_BUSTYPE_SSB:
offset += current_coreidx * SSB_CORE_SIZE;
@@ -174,7 +177,11 @@ static u32 scan_read32(struct ssb_bus *bus, u8 current_coreidx,
offset -= 0x800;
} else
ssb_pcmcia_switch_segment(bus, 0);
- break;
+ spin_lock_irqsave(&bus->bar_lock, flags);
+ lo = readw(bus->mmio + offset);
+ hi = readw(bus->mmio + offset + 2);
+ spin_unlock_irqrestore(&bus->bar_lock, flags);
+ return lo | (hi << 16);
case SSB_BUSTYPE_SDIO:
offset += current_coreidx * SSB_CORE_SIZE;
return ssb_sdio_scan_read32(bus, offset);

2009-11-06 17:10:51

by Michael Büsch

Subject: Re: [PATCH] SSB: fix 32 bit PCMCIA access.

On Friday 06 November 2009 16:56:05 Martin Fuzzey wrote:
> The scan function was using 32 bit access which does not
> work on 16bit CF cards.
>
> This patch corrects this by doing two 16 bit reads like
> ssb_pcmcia_read32 already does (unfortunately we don't
> have a struct ssb_device to use that directly).
>
> Signed-off-by: Martin Fuzzey <[email protected]>
>
> ---
>
> drivers/ssb/scan.c | 9 ++++++++-
> 1 files changed, 8 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/ssb/scan.c b/drivers/ssb/scan.c
> index b74212d..6721fa8 100644
> --- a/drivers/ssb/scan.c
> +++ b/drivers/ssb/scan.c
> @@ -162,6 +162,9 @@ static u8 chipid_to_nrcores(u16 chipid)
> static u32 scan_read32(struct ssb_bus *bus, u8 current_coreidx,
> u16 offset)
> {
> + unsigned long flags;
> + u32 lo, hi;
> +
> switch (bus->bustype) {
> case SSB_BUSTYPE_SSB:
> offset += current_coreidx * SSB_CORE_SIZE;
> @@ -174,7 +177,11 @@ static u32 scan_read32(struct ssb_bus *bus, u8 current_coreidx,
> offset -= 0x800;
> } else
> ssb_pcmcia_switch_segment(bus, 0);
> - break;
> + spin_lock_irqsave(&bus->bar_lock, flags);
> + lo = readw(bus->mmio + offset);
> + hi = readw(bus->mmio + offset + 2);
> + spin_unlock_irqrestore(&bus->bar_lock, flags);
> + return lo | (hi << 16);
> case SSB_BUSTYPE_SDIO:
> offset += current_coreidx * SSB_CORE_SIZE;
> return ssb_sdio_scan_read32(bus, offset);

Thanks for spotting this. This really looks like a bug.
I'll test this patch on my device and remove the unnecessary locks and then resubmit upstream.

Next time, please make sure to Cc maintainers. See the MAINTAINERS file.

--
Greetings, Michael.