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SubjectRe: [PATCH] wireless: introduce POWEROF2_BLOCKSIZE_ONLY option
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On Thu, Feb 5, 2009 at 11:03 PM, Dan Williams <dcbw@redhat.com> wrote:
> On Thu, 2009-02-05 at 15:30 +0800, Bryan Wu wrote:
>> From: Cliff Cai <cliff.cai@analog.com>
>>
>> Introduce POWEROF2_BLOCKSIZE_ONLY option for those SD/SDIO host
>> which only support transferring block with size of power-of-2
>
> Is the point here to avoid copying in the controller code? As with the
> other patches on libertas-dev, I really dislike adding code to *every
> SDIO driver* just because the host has certain restrictions. I'd much
> rather that the host/controller code became aware of it's own
> restrictions, and exposed those generically to drivers above it.
> Without a KConfig option.
>
> Seriously. The host knows what it needs. The code to handle that
> should go in the host.
>

I agree here.

> How about adding a method like "sdio_align_size" that takes the
> controller's constraints into account? That seems a lot cleaner than
> adding #define/KConfig junk to every SDIO driver in the kernel. One
> less codepath to test, makes your life and all our lives easier.
>

So we plan to add method ".sdio_align_size" to SDIO stack.
And Blackfin host driver will implement this method while others will
implement this as a dummy function.

In libertas, we need to call this method to take this constraints into account.

Thanks
-Bryan


>> [ Bryan Wu <cooloney@kernel.org>:
>> - remove some useless coding style cleanup
>> - using roundup() function as upstream does
>> ]
>>
>> Signed-off-by: Cliff Cai <cliff.cai@analog.com>
>> Signed-off-by: Bryan Wu <cooloney@kernel.org>
>> ---
>> drivers/net/wireless/Kconfig | 6 ++++++
>> drivers/net/wireless/libertas/if_sdio.c | 16 ++++++++++++++++
>> 2 files changed, 22 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/net/wireless/Kconfig b/drivers/net/wireless/Kconfig
>> index e4f9f74..a2685fa 100644
>> --- a/drivers/net/wireless/Kconfig
>> +++ b/drivers/net/wireless/Kconfig
>> @@ -151,6 +151,12 @@ config LIBERTAS_SDIO
>> ---help---
>> A driver for Marvell Libertas 8385 and 8686 SDIO devices.
>>
>> +config POWEROF2_BLOCKSIZE_ONLY
>> + bool "Support transferring block with size of power-of-2 only"
>> + depends on LIBERTAS_SDIO
>> + ---help---
>> + For SD/SDIO host which only supports transferring block with size of power-of-2.
>> +
>> config LIBERTAS_DEBUG
>> bool "Enable full debugging output in the Libertas module."
>> depends on LIBERTAS
>> diff --git a/drivers/net/wireless/libertas/if_sdio.c b/drivers/net/wireless/libertas/if_sdio.c
>> index 4519d73..5efc056 100644
>> --- a/drivers/net/wireless/libertas/if_sdio.c
>> +++ b/drivers/net/wireless/libertas/if_sdio.c
>> @@ -272,6 +272,11 @@ static int if_sdio_card_to_host(struct if_sdio_card *card)
>> */
>> chunk = sdio_align_size(card->func, size);
>>
>> +/* For SD/SDIO host which only supports transferring block with size of power-of-2 */
>> +#if defined(CONFIG_POWEROF2_BLOCKSIZE_ONLY)
>> + chunk = (chunk + card->func->cur_blksize - 1) /
>> + card->func->cur_blksize * card->func->cur_blksize;
>> +#endif
>> ret = sdio_readsb(card->func, card->buffer, card->ioport, chunk);
>> if (ret)
>> goto out;
>> @@ -581,8 +586,14 @@ static int if_sdio_prog_real(struct if_sdio_card *card)
>> lbs_deb_sdio("sending %d bytes (%d bytes) chunk\n",
>> chunk_size, (chunk_size + 31) / 32 * 32);
>> */
>> +/* For SD/SDIO host which only supports transferring block with size of power-of-2 */
>> +#if defined(CONFIG_POWEROF2_BLOCKSIZE_ONLY)
>> + ret = sdio_writesb(card->func, card->ioport,
>> + chunk_buffer, roundup(chunk_size, 256);
>> +#else
>> ret = sdio_writesb(card->func, card->ioport,
>> chunk_buffer, roundup(chunk_size, 32));
>> +#endif
>> if (ret)
>> goto release;
>>
>> @@ -699,6 +710,11 @@ static int if_sdio_host_to_card(struct lbs_private *priv,
>> */
>> size = sdio_align_size(card->func, nb + 4);
>>
>> +/* For SD/SDIO host which only supports transferring block with size of power-of-2 */
>> +#if defined(CONFIG_POWEROF2_BLOCKSIZE_ONLY)
>> + size = (size + card->func->cur_blksize - 1) /
>> + card->func->cur_blksize * card->func->cur_blksize;
>> +#endif
>> packet = kzalloc(sizeof(struct if_sdio_packet) + size,
>> GFP_ATOMIC);
>> if (!packet) {
>
>


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