brcmfmac: sdio: shorten retry loop in brcmf_sdio_kso_control()

In brcmf_sdio_kso_control() there is a retry loop as hardware may take
time to settle. However, when the call to brcmf_sdiod_regrb() returns
an error it is due to SDIO access failure and it makes no sense to wait
for hardware to settle. This patch aborts the loop after a number of
subsequent access errors.

Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
index 589a49cd9cd5..b892dac70f4b 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
@@ -313,6 +313,7 @@ struct rte_console {
 
 #define KSO_WAIT_US 50
 #define MAX_KSO_ATTEMPTS (PMU_MAX_TRANSITION_DLY/KSO_WAIT_US)
+#define BRCMF_SDIO_MAX_ACCESS_ERRORS    5
 
 /*
  * Conversion of 802.1D priority to precedence level
@@ -677,6 +678,7 @@ brcmf_sdio_kso_control(struct brcmf_sdio *bus, bool on)
 {
         u8 wr_val = 0, rd_val, cmp_val, bmask;
         int err = 0;
+        int err_cnt = 0;
         int try_cnt = 0;
 
         brcmf_dbg(TRACE, "Enter: on=%d\n", on);
@@ -712,9 +714,14 @@ brcmf_sdio_kso_control(struct brcmf_sdio *bus, bool on)
                  */
                 rd_val = brcmf_sdiod_regrb(bus->sdiodev, SBSDIO_FUNC1_SLEEPCSR,
                                            &err);
-                if (((rd_val & bmask) == cmp_val) && !err)
+                if (!err) {
+                        if ((rd_val & bmask) == cmp_val)
+                                break;
+                        err_cnt = 0;
+                }
+                /* bail out upon subsequent access errors */
+                if (err && (err_cnt++ > BRCMF_SDIO_MAX_ACCESS_ERRORS))
                         break;
-
                 udelay(KSO_WAIT_US);
                 brcmf_sdiod_regwb(bus->sdiodev, SBSDIO_FUNC1_SLEEPCSR,
                                   wr_val, &err);