Re: [PATCH v2] libertas: Fix sd8686 firmware reload

[Dan Williams <dcbw@redhat.com>]

On Wed, 2010-10-27 at 15:20 +0100, Daniel Drake wrote:
> From: Paul Fox <pgf@laptop.org>
> 
> For the SD8686, we cannot rely on the scratch register to read the firmware
> load status, because the same register is used for storing RX packet length.
> Broaden the check to account for this.
> 
> The module can now be unloaded/reloaded successfully.
> 
> Based on the implementation from libertas_tf.
> 
> Signed-off-by: Daniel Drake <dsd@laptop.org>

Acked-by: Dan Williams <dcbw@redhat.com>

> ---
>  drivers/net/wireless/libertas/if_sdio.c |   32 ++++++++++++++++++++++++++++--
>  1 files changed, 29 insertions(+), 3 deletions(-)
> 
> v2: rebase on latest pull to overcome a trivial conflict generated by another
> recent change
> 
> diff --git a/drivers/net/wireless/libertas/if_sdio.c b/drivers/net/wireless/libertas/if_sdio.c
> index 296fd00..f41a5ab 100644
> --- a/drivers/net/wireless/libertas/if_sdio.c
> +++ b/drivers/net/wireless/libertas/if_sdio.c
> @@ -684,18 +684,40 @@ static int if_sdio_prog_firmware(struct if_sdio_card *card)
>  
>  	lbs_deb_enter(LBS_DEB_SDIO);
>  
> +	/*
> +	 * Disable interrupts
> +	 */
> +	sdio_claim_host(card->func);
> +	sdio_writeb(card->func, 0x00, IF_SDIO_H_INT_MASK, &ret);
> +	sdio_release_host(card->func);
> +
>  	sdio_claim_host(card->func);
>  	scratch = if_sdio_read_scratch(card, &ret);
>  	sdio_release_host(card->func);
>  
> +	lbs_deb_sdio("firmware status = %#x\n", scratch);
> +	lbs_deb_sdio("scratch ret = %d\n", ret);
> +
>  	if (ret)
>  		goto out;
>  
> -	lbs_deb_sdio("firmware status = %#x\n", scratch);
>  
> +	/*
> +	 * The manual clearly describes that FEDC is the right code to use
> +	 * to detect firmware presence, but for SD8686 it is not that simple.
> +	 * Scratch is also used to store the RX packet length, so we lose
> +	 * the FEDC value early on. So we use a non-zero check in order
> +	 * to validate firmware presence.
> +	 * Additionally, the SD8686 in the Gumstix always has the high scratch
> +	 * bit set, even when the firmware is not loaded. So we have to
> +	 * exclude that from the test.
> +	 */
>  	if (scratch == IF_SDIO_FIRMWARE_OK) {
>  		lbs_deb_sdio("firmware already loaded\n");
>  		goto success;
> +	} else if ((card->model == IF_SDIO_MODEL_8686) && (scratch & 0x7fff)) {
> +		lbs_deb_sdio("firmware may be running\n");
> +		goto success;
>  	}
>  
>  	ret = lbs_get_firmware(&card->func->dev, lbs_helper_name, lbs_fw_name,
> @@ -709,10 +731,14 @@ static int if_sdio_prog_firmware(struct if_sdio_card *card)
>  	if (ret)
>  		goto out;
>  
> +	lbs_deb_sdio("Helper firmware loaded\n");
> +
>  	ret = if_sdio_prog_real(card, mainfw);
>  	if (ret)
>  		goto out;
>  
> +	lbs_deb_sdio("Firmware loaded\n");
> +
>  success:
>  	sdio_claim_host(card->func);
>  	sdio_set_block_size(card->func, IF_SDIO_BLOCK_SIZE);
> @@ -1042,8 +1068,6 @@ static int if_sdio_probe(struct sdio_func *func,
>  	priv->exit_deep_sleep = if_sdio_exit_deep_sleep;
>  	priv->reset_deep_sleep_wakeup = if_sdio_reset_deep_sleep_wakeup;
>  
> -	priv->fw_ready = 1;
> -
>  	sdio_claim_host(func);
>  
>  	/*
> @@ -1064,6 +1088,8 @@ static int if_sdio_probe(struct sdio_func *func,
>  	if (ret)
>  		goto reclaim;
>  
> +	priv->fw_ready = 1;
> +
>  	/*
>  	 * FUNC_INIT is required for SD8688 WLAN/BT multiple functions
>  	 */