*
* Copyright (C) 2003-2004 Russell King, All Rights Reserved.
* SD support Copyright (C) 2004 Ian Molton, All Rights Reserved.
- * Copyright (C) 2005-2007 Pierre Ossman, All Rights Reserved.
+ * Copyright (C) 2005-2008 Pierre Ossman, All Rights Reserved.
* MMCv4 support Copyright (C) 2006 Philip Langdale, All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
}
EXPORT_SYMBOL(mmc_set_data_timeout);
+/**
+ * mmc_align_data_size - pads a transfer size to a more optimal value
+ * @card: the MMC card associated with the data transfer
+ * @sz: original transfer size
+ *
+ * Pads the original data size with a number of extra bytes in
+ * order to avoid controller bugs and/or performance hits
+ * (e.g. some controllers revert to PIO for certain sizes).
+ *
+ * Returns the improved size, which might be unmodified.
+ *
+ * Note that this function is only relevant when issuing a
+ * single scatter gather entry.
+ */
+unsigned int mmc_align_data_size(struct mmc_card *card, unsigned int sz)
+{
+ /*
+ * FIXME: We don't have a system for the controller to tell
+ * the core about its problems yet, so for now we just 32-bit
+ * align the size.
+ */
+ sz = ((sz + 3) / 4) * 4;
+
+ return sz;
+}
+EXPORT_SYMBOL(mmc_align_data_size);
+
/**
* __mmc_claim_host - exclusively claim a host
* @host: mmc host to claim
/*
* linux/drivers/mmc/core/sdio_io.c
*
- * Copyright 2007 Pierre Ossman
+ * Copyright 2007-2008 Pierre Ossman
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
EXPORT_SYMBOL_GPL(sdio_set_block_size);
+/**
+ * sdio_align_size - pads a transfer size to a more optimal value
+ * @func: SDIO function
+ * @sz: original transfer size
+ *
+ * Pads the original data size with a number of extra bytes in
+ * order to avoid controller bugs and/or performance hits
+ * (e.g. some controllers revert to PIO for certain sizes).
+ *
+ * If possible, it will also adjust the size so that it can be
+ * handled in just a single request.
+ *
+ * Returns the improved size, which might be unmodified.
+ */
+unsigned int sdio_align_size(struct sdio_func *func, unsigned int sz)
+{
+ unsigned int orig_sz;
+ unsigned int blk_sz, byte_sz;
+ unsigned chunk_sz;
+
+ orig_sz = sz;
+
+ /*
+ * Do a first check with the controller, in case it
+ * wants to increase the size up to a point where it
+ * might need more than one block.
+ */
+ sz = mmc_align_data_size(func->card, sz);
+
+ /*
+ * If we can still do this with just a byte transfer, then
+ * we're done.
+ */
+ if ((sz <= func->cur_blksize) && (sz <= 512))
+ return sz;
+
+ if (func->card->cccr.multi_block) {
+ /*
+ * Check if the transfer is already block aligned
+ */
+ if ((sz % func->cur_blksize) == 0)
+ return sz;
+
+ /*
+ * Realign it so that it can be done with one request,
+ * and recheck if the controller still likes it.
+ */
+ blk_sz = ((sz + func->cur_blksize - 1) /
+ func->cur_blksize) * func->cur_blksize;
+ blk_sz = mmc_align_data_size(func->card, blk_sz);
+
+ /*
+ * This value is only good if it is still just
+ * one request.
+ */
+ if ((blk_sz % func->cur_blksize) == 0)
+ return blk_sz;
+
+ /*
+ * We failed to do one request, but at least try to
+ * pad the remainder properly.
+ */
+ byte_sz = mmc_align_data_size(func->card,
+ sz % func->cur_blksize);
+ if ((byte_sz <= func->cur_blksize) && (byte_sz <= 512)) {
+ blk_sz = sz / func->cur_blksize;
+ return blk_sz * func->cur_blksize + byte_sz;
+ }
+ } else {
+ /*
+ * We need multiple requests, so first check that the
+ * controller can handle the chunk size;
+ */
+ chunk_sz = mmc_align_data_size(func->card,
+ min(func->cur_blksize, 512u));
+ if (chunk_sz == min(func->cur_blksize, 512u)) {
+ /*
+ * Fix up the size of the remainder (if any)
+ */
+ byte_sz = orig_sz % chunk_sz;
+ if (byte_sz) {
+ byte_sz = mmc_align_data_size(func->card,
+ byte_sz);
+ }
+
+ return (orig_sz / chunk_sz) * chunk_sz + byte_sz;
+ }
+ }
+
+ /*
+ * The controller is simply incapable of transferring the size
+ * we want in decent manner, so just return the original size.
+ */
+ return orig_sz;
+}
+EXPORT_SYMBOL_GPL(sdio_align_size);
+
/* Split an arbitrarily sized data transfer into several
* IO_RW_EXTENDED commands. */
static int sdio_io_rw_ext_helper(struct sdio_func *func, int write,
/*
* linux/drivers/net/wireless/libertas/if_sdio.c
*
- * Copyright 2007 Pierre Ossman
+ * Copyright 2007-2008 Pierre Ossman
*
* Inspired by if_cs.c, Copyright 2007 Holger Schurig
*
/*
* The transfer must be in one transaction or the firmware
- * goes suicidal.
+ * goes suicidal. There's no way to guarantee that for all
+ * controllers, but we can at least try.
*/
- chunk = size;
- if ((chunk > card->func->cur_blksize) || (chunk > 512)) {
- chunk = (chunk + card->func->cur_blksize - 1) /
- card->func->cur_blksize * card->func->cur_blksize;
- }
+ chunk = sdio_align_size(card->func, size);
ret = sdio_readsb(card->func, card->buffer, card->ioport, chunk);
if (ret)
/*
* The transfer must be in one transaction or the firmware
- * goes suicidal.
+ * goes suicidal. There's no way to guarantee that for all
+ * controllers, but we can at least try.
*/
- size = nb + 4;
- if ((size > card->func->cur_blksize) || (size > 512)) {
- size = (size + card->func->cur_blksize - 1) /
- card->func->cur_blksize * card->func->cur_blksize;
- }
+ size = sdio_align_size(card->func, nb + 4);
packet = kzalloc(sizeof(struct if_sdio_packet) + size,
GFP_ATOMIC);
struct mmc_command *, int);
extern void mmc_set_data_timeout(struct mmc_data *, const struct mmc_card *);
+extern unsigned int mmc_align_data_size(struct mmc_card *, unsigned int);
extern int __mmc_claim_host(struct mmc_host *host, atomic_t *abort);
extern void mmc_release_host(struct mmc_host *host);
/*
* include/linux/mmc/sdio_func.h
*
- * Copyright 2007 Pierre Ossman
+ * Copyright 2007-2008 Pierre Ossman
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
extern int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler);
extern int sdio_release_irq(struct sdio_func *func);
+extern unsigned int sdio_align_size(struct sdio_func *func, unsigned int sz);
+
extern unsigned char sdio_readb(struct sdio_func *func,
unsigned int addr, int *err_ret);
extern unsigned short sdio_readw(struct sdio_func *func,
projects / linux-2.6 / commitdiff