PLX_CONTROL
u32 old_value = readl(card->plx + PLX_CONTROL) & ~PLX_CTL_RESET;
writel(old_value | PLX_CTL_RESET, card->plx + PLX_CONTROL);
readl(card->plx + PLX_CONTROL); /* wait for posted write */
writel(old_value, card->plx + PLX_CONTROL);
readl(card->plx + PLX_CONTROL); /* wait for posted write */