From: Rafał Miłecki <[email protected]> BCM53573 is a new series of Broadcom's SoCs. It's based on ARM and uses this old ChipCommon-based flash access. Early tests resulted in flash corruptions that were tracked down to using cached MMIO for flash read access. Switch to ioremap_nocache conditionally to support BCM53573 and don't break performance on old MIPS devices.
Signed-off-by: Rafał Miłecki <[email protected]> --- drivers/mtd/devices/bcm47xxsflash.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/devices/bcm47xxsflash.c b/drivers/mtd/devices/bcm47xxsflash.c index 1c65c15..514be04 100644 --- a/drivers/mtd/devices/bcm47xxsflash.c +++ b/drivers/mtd/devices/bcm47xxsflash.c @@ -296,16 +296,30 @@ static int bcm47xxsflash_bcma_probe(struct platform_device *pdev) dev_err(dev, "can't request region for resource %pR\n", res); return -EBUSY; } - b47s->window = ioremap_cache(res->start, resource_size(res)); - if (!b47s->window) { - dev_err(dev, "ioremap failed for resource %pR\n", res); - return -ENOMEM; - } b47s->bcma_cc = container_of(sflash, struct bcma_drv_cc, sflash); b47s->cc_read = bcm47xxsflash_bcma_cc_read; b47s->cc_write = bcm47xxsflash_bcma_cc_write; + /* + * On old MIPS devices cache was magically invalidated when needed, + * allowing us to use cached access and gain some performance. Trying + * the same on ARM based BCM53573 results in flash corruptions, we need + * to use uncached access for it. + * + * It may be arch specific, but right now there is only 1 ARM SoC using + * this driver, so let's follow Broadcom's reference code and check + * ChipCommon revision. + */ + if (b47s->bcma_cc->core->id.rev == 54) + b47s->window = ioremap_nocache(res->start, resource_size(res)); + else + b47s->window = ioremap_cache(res->start, resource_size(res)); + if (!b47s->window) { + dev_err(dev, "ioremap failed for resource %pR\n", res); + return -ENOMEM; + } + switch (b47s->bcma_cc->capabilities & BCMA_CC_CAP_FLASHT) { case BCMA_CC_FLASHT_STSER: b47s->type = BCM47XXSFLASH_TYPE_ST; -- 1.8.4.5
